Natalina beyrichi (Martens, 1890).
Figs 3D, 8A, 14E, 15A, 30-32
Aerope beyrichi: Martens 1890: 85; 1894: 1; 1897: 35, pl. 6, figs 1-3. Type loc.: Pondoland [C. Beyrich].
Natalina beyrichi: Melvill & Ponsonby 1898: 170; Sturany 1898: 30; Mollendorff 1903: 21, pl. 4, figs 1-3; Connolly 1912: 90; 1939: 106, pl. 4, figs 1-3; Herbert & Kilburn 2004: 222.
Etymology: Named for Conrad Beyrich (dates not known), a German engineer. In 1888 he travelled through Pondoland (north-eastern E. Cape) with fellow German, Frans Ewald Bachmann, visiting localities from the Mtamvuna River south to Port St Johns.
Identification: A relatively easily identified species on account of its depressed shape, comparatively strongly sculptured base, wide umbilicus and coastal distribution in the north-eastern E. Cape; a range which overlaps only with that of N. cafra eumacta which is taller, more globose and has a narrower, partially obscured umbilicus.
[FIGURE 30 OMITTED]
Description (Fig. 30): Shell large and relatively depressed, thin and fragile; periphery at or below mid-whorl; suture somewhat above mid-whorl, but descending to a variable degree prior to aperture at maturity. Protoconch diameter typically 7-8 mm, but its limit difficult to determine in many specimens. Apical surface sculptured by close-set axial riblets which remain obvious on base; junction between dull upper surface and more shiny base forming a relatively distinct line at the periphery; umbilicus wide, not obscured at all by columella lip when viewed basally; long axis of aperture more or less horizontal or only slightly oblique; outer lip not thickened.
Periostracum olive-green to olive-brown with frequent radial bands in darker shades, particularly on last whorl.
Dimensions: Largest specimen (NMSA W5414, Port St Johns), diameter 63.1 mm; H:D of adults 0.57-0.74 (N=28).
Living animal (Fig. 15A): Head-foot grey to greyish brown or brown, dorsal neck region and optic tentacles somewhat darker, generally lacking pale longitudinal stripes extending backward from optic tentacles; sides of foot paler, particularly beneath shell; pedal margin tinged with orange, tail sometimes brightly so; mantle edge bright orange. Radula (Fig. 31): Formula 1+5+~22 (N=2); length in adult 34-38 mm, with 44-56 transverse rows of teeth.
Distal genitalia: Epiphallus with a well-developed bulla near its junction with vas deferens; internally this has a hollow central core continuous with the epiphallus lumen, its junction with the latter being bounded by a raised circular flange.
Spermatophore (Fig. 14E): Well preserved allospermatophores have been found in two specimens, collected in early November (NMSA W4123, W4125). Straightened length 18-26 mm. In general form these resemble those of N. cafra subspp. and were strongly curved in situ in the oviduct caecum. Notably, they differ in having a well-developed thumb-like projection on the outer side, at the base of the recurved tail region. This is more substantial than the similar projection sometimes seen in the spermatophores of N. c. eumacta and N. c. natalensis. It is clearly formed in the epiphallus bulla.
[FIGURE 31 OMITTED]
Type material: Nine syntypes in Berlin Museum (MNHU: 42394). We designate the specimen figured by Martens (1897) and re-illustrated here (Figs 30A-C) to be the lectotype, diameter 59.5 mm, height 38.0 mm (Martens gave the dimensions as diameter 62 mm, height 40 mm, but this may refer to the largest specimen rather than the one figured). Connolly's mention of the 'type in Zool. Mus. Berlin' (Connolly 1912) does not constitute a lectotype designation since he did not specify any one specimen in particular.
Additional material examined (all NMSA unless otherwise indicated): SOUTH AFRICA: E. Cape: Mkambati Nat. Res., 'Super Bowl' forest at junction of Msikaba and KwaDlambu rivers (31.2955[degrees]S:29.9292[degrees]E), indigenous forest, in leaf-litter, M. Bursey, 05/iii/2001 (V9220 body only, shell in ELM D13333); ditto (31.2955[degrees]S:29.9292[degrees]E), indigenous forest, in leaf-litter beneath Trichilia dregeana Sonder, D. Herbert, 05/ iii/2001 (V8916); Mbotyi, various sites beside road through upper section of forested scarp (Ntsubane Forest) (31.4298[degrees]S:29.7261[degrees]E), coastal forest, in leaf-litter, D. Herbert, 03/iii/2003 (W0591); Mbotyi Forest (31.43107[degrees]S:29.72656[degrees]E), ca 300 m, indigenous forest, in leaf-litter, A. Moussalli & D. Stuart-Fox, 3/xi/ 2005 (W4123); Magwa Falls, Egossa Forest (31.4333[degrees]S:29.6333[degrees]E), ca 500 m, R. Botha, 08/vii/2006 (ELM W02995); Port St Johns area, east bank of Mzimvubu R., 26 km upstream of mouth (31.509722[degrees]S: 29.448883[degrees]E), M. Bursey, 24/i/2006 (ELM D14771); Mntafufu, north side of river (31.5559[degrees]S:29.6261[degrees]E), coastal forest, in leaf-litter, one individual found eating Gittenedouardia carinifera (Melvill & Ponsonby, 1897), D. Herbert, L. Davis & M. Bursey, 23/iv/2005 (W1831, W2969, W2970, W3025); ditto, south side of river (31.55021[degrees]S:29.61777[degrees]E), coastal scarp forest, amongst talus and leaf-litter at base of road cutting, D. Herbert & M. Bursey, 29/iv/2004 (W1823); Port St Johns, east bank, 1 km from river mouth (31.60833 [degrees]S: 29.55000[degrees]E), R. Botha, 06/vii/2006 (ELM W03000); ditto, Isinuka sulphur springs and travertine deposit (31.60953[degrees]S:29.47989[degrees]E), woodland/forest, in leaf-litter, D. Herbert, 04/iii/2003 (W0538); ditto, southern side of Mt. Thesiger (31.61185[degrees]S:29.50202[degrees]E), scarp forest, in leaf-litter, D. Herbert, L. Davis & M. Bursey, 23/iv/2005 (W3029); ditto, north of Mzimvubu R. (31.61519[degrees]S:29.54526[degrees]E), indigenous forest, in leaflitter, A. Moussalli & D. Stuart-Fox, 08/xi/2005 (W5414); Port St Johns (not further localised) (A7044, A7130, V2013, E7862, BMNH 19184.108.40.2064); ditto, Second Beach (31.64819[degrees]S:29.51746[degrees]E), 100 m, coastal forest, in leaf-litter, A. Moussalli & D. Stuart-Fox, 05/xi/2005 (W4125, W5413); ditto, Silaka Nat. Res. (31.64903[degrees]S:29.50339[degrees]E), M. Bursey, 05/iii/2003 (ELM D13835); Nothintsila, ca 20 km NW of Hluleka Nat. Res. (31.74733[degrees]S:29.20008[degrees]E), 395 m, indigenous forest, in leaf-litter, A. Moussalli & D. Stuart- Fox, 14/xi/2005 (W4734); Mpande (31.74738[degrees]S:29.37078[degrees]E), coastal forest north of river mouth, in leaf- litter, D. Herbert, L. Davis & M. Bursey, 21/iv/2005 (W2849, W2870, W2872, W2873); Hluleka Nat. Res. (31.8203[degrees]S:29.30303[degrees]E), coastal forest, in leaf-litter, D. Herbert, L. Davis & M. Bursey, 20/iv/2005 (W3023, W2895, W2896); ditto (31.82333[degrees]S:29.30550[degrees]E), coastal forest, in leaf-litter, D. Herbert, L. Davis & M. Bursey, 20/iv/2005 (W3047); Xora R. mouth area, Kwaqana Forest (32.13833[degrees]S:28.98750[degrees]E), M. Bursey, 15/ix/2005 (ELM D14544); Xora River mouth (32.150[degrees]S:28.983[degrees]E), washed into mangroves, V. van der Walt, 1997 (V5311); Xora, east bank of Xora river (32.15167[degrees]S:28.99222[degrees]E), M. Bursey, 26/viii/2001 (ELM D13345); ditto, Kumqolo Forest (32.15888[degrees]S:28.98481[degrees]E), M. Bursey, 12/vii/2003 (ELM D13686); ditto, Kumqolo Forest, small patch of coastal forest on west bank of river (32.159[degrees]S:28.985[degrees]E), in leaflitter, M. Bursey, 14/ix/2005 (W5395); The Haven Nat. Res., vicinity of camp ground (32.24435[degrees]S:28.90600[degrees]E), 15 m, coastal dune forest, in leaf-litter, A. Moussalli & D. Stuart-Fox, 16/xi/2005 (W4149); Dwesa Nat. Res. (32.280[degrees]S:28.842[degrees]E), coastal forest, in leaf-litter, D. Herbert, 06/iii/2000 (V7869); Qora, east bank of river (32.433[degrees]S:28.667[degrees]E), M. Bursey, 21/ii/2006 (ELM D14798); Mpetu area, Tyityaba, Belladonna farm (32.56833[degrees]S:28.12500[degrees]E), 340 m, C. Vernon, 26/vii/1986 (ELM D10040).
Distribution (Fig. 32): A restricted-range E. Cape endemic, known only from the coastal hinterland between Mkambati Nature Reserve and the Kei River valley (Mpetu area). Its distribution seldom reaches far inland (maximum recorded distance from coast [+ or -] 30 km) and extends along the coast for [+ or -]230 km; occurs from sea-level to 500 m.
Habitat: Primarily associated with scarp forests in the Transkei Coastal Belt, but extending also into forest patches within the Eastern Valley Bushveld; in leaf-litter and under logs; locally common.
Notes: Natalina beyrichi is unlikely to be confused with any other species on account of its depressed, widely umbilicate shell and coastal distribution in the north-eastern E. Cape. There is some variation in shell height, with specimens from the Hluleka area often having a more elevated spire and in addition a slightly coarser sculpture (Fig. 30G). However, specimens of intermediate height are known and all possess the wide, open umbilicus typical of the species. In analyses of molecular data, elevated specimens cluster together with more typical specimens. Not surprisingly, given its restricted coastal distribution, genetic diversity within N. beyrichi is limited (Moussalli et al. 2009). The coastal forest habitats favoured by the species would have been largely continuous prior to the impact of humans, facilitating gene flow and preventing the differentiation of local subpopulations. In the south of its range, the distribution of N. beyrichi overlaps with that of N. cafra eumacta, but that taxon is markedly more globose. The zone of sympatry extends for approximately 70 km, between the Kei and Mbashe rivers, but the two taxa have been found to co-occur at few localities. Where they are syntopic, they remain easily separable with no evidence of intergrading.
Individuals have been collected consuming molluscan prey (e.g., Gittenedouardia spp., Cerastidae), but microchaetid earthworms (Microchaetus pondoanus Michaelsen, 1913) are often abundant in the coastal forests of Transkei (Plisko 2003, and pers. observ.) and these may also be important diet items. Captive animals have readily consumed such prey.
Conservation: Natalina beyrichi is a characteristic element of the coastal forests of the Transkei region and is currently listed as Critically Endangered [CR B1+2c] (IUCN 2010). This is due to its restricted distribution and the threats to coastal forest habitats in much of its range. Such threats are on-going and include mining, subsistence harvesting, invasive plants and trampling by cattle. However, despite its limited range, the species may be locally relatively common. It is protected in conserved areas such as Mkambati, Hluleka and Dwesa nature reserves, but the first and last of these are at or near the ends of its range. Populations in the Mbotyi to Port St Johns area, where it is currently most common, are not protected.
[FIGURE 32 OMITTED]
Natalina quekettiana complex
In addition to the large and conspicuous Natalina s.s. species discussed thus far, are three further species described from KwaZulu-Natal. These are all of smaller size and appear to be rare. In two cases they are known solely from the original samples, and only N. quekettiana has been collected again subsequent to its original description. However, on-going field work has brought to light additional small-shelled, but clearly adult Natalina specimens from a number of other localities in KwaZulu-Natal (Fig. 33). These are similar to the described taxa, but not clearly conspecific with any one of them. We have attempted to clarify this matter through analysis of DNA sequence data, but have been hindered in this by being unable to obtain fresh topotypic material of two of the described species (N. inhluzana and N. reenenensis), despite targeted attempts. We have, however, been able to obtain sequence data from topotypic material of N. quekettiana and a number of the indeterminate specimens from other localities.
From analyses of these data (Moussalli et al. 2009), it is clear that the small-shelled specimens collectively comprise a monophyletic lineage within Natalina, which we term the N. quekettiana complex. This is sister to the clade comprising N. cafra and N. beyrichi (Fig. 1). In terms of shell morphology, radula dentition, body coloration and genetic make up, this complex exhibits considerable internal diversity, although, with the exception of the epiphallus, the genital anatomy is the same. The spermatophore is known for only one subspecies, but this differs greatly from that of the larger Natalina s.s. species and Natalina (Tongalina) in bearing well-developed, lobate, scale-like spines. This differing spermatophore morphology is reflected in the internal structure of the epiphallus and, since this is similar in all members of the complex for which preserved material is available, it is likely that the presence of scale-like spines on the spermatophore will prove to be an autapomorphic trait for this clade as a whole (the spines on the Afrorhytida spermatophore are of a very different form).
The molecular data identified four allopatric subclades (Fig. 1), one comprising material from central and south-western Zululand, a second from the mist-belt regions of the KwaZulu-Natal Midlands, and two others from the central KwaZulu-Natal Drakensberg. The first two are sister taxa and can be differentiated from each other morphologically in terms of size and radula dentition. As a pair they comprise a mid-altitude radiation (600-1500 m). The two other subclades, from higher altitude forests in the foothills of the central Drakensberg (1350-1650 m), however, show no obvious or consistent differences in shell form (which is confusingly variable in the few specimens available) or radula dentition. Yet despite this and their geographical proximity, they are evidently not closely related, the one being sister to the mid-altitude subclade and the other representing a deeply divergent lineage arising at the base of the N. quekettiana clade. Neither appear to be referable to the similarly high altitude taxon N. reenenensis on account of differences in radula dentition.
[FIGURE 33 OMITTED]
This situation is clearly complicated and in need of further investigation, but for the present, we chose to treat this material as a single complex. However, in order to recognise the lineages identified through analyses of molecular data (in some cases supported by morphology), we propose to treat these as subspecies within a broadly interpreted Natalina quekettiana, the earliest available species-group name within the complex. We maintain Natalina reenenensis as a distinct species simply because we have no data upon which to base a change in its status. It is unique within the N. quekettiana complex in having only five pairs of lateral teeth per transverse row of the radula. We also have no new data concerning N. inhluzana, and treat this as a separate entity too, but we strongly suspect that it is a synonym of N. quekettiana quekettiana (see below).
[FIGURE 34 OMITTED]
In addition to the above, are further small-shelled specimens (Fig. 34) from escarpment-edge habitats in Mpumalanga and Swaziland (locality details given below). These are shell-only samples and while we can be moderately confident that they belong to the N. quekettiana complex, we cannot reliably assign them to any of the taxa discussed below. They do, however, indicate that this complex ranges beyond KwaZulu-Natal along the north-eastern Drakensberg escarpment.
[FIGURE 35 OMITTED]
As a whole, the N. quekettiana complex is evidently confined to wet forest habitats, primarily Afrotemperate (montane) and mist-belt forests, but extends also into lower altitude scarp forest in southern Zululand (Fig. 33). Given this habitat specialisation, the distribution of the taxon is likely to be highly fragmented with many populations and perhaps species restricted to isolated forest islands within the rainforest archipelago. This patchy pattern is concordant with the considerable genetic diversity mentioned above, even between geographically proximate populations, for example those in central KwaZulu-Natal Drakensberg (Cathedral Peak vs Injasuthi-Monk's Cowl). It is thought that this derives from sequential isolation events associated with Plio-Pleistocene glacial cycles (see biogeographic summary).
Unidentified material belonging to the Natalina quekettiana complex: SOUTH AFRICA: Mpumalanga: Mariepskop Forest (24.56683[degrees]S:30.86232[degrees]E), 1520 m, mist-belt forest, J. Horn, 28/ii/2005 (NMSA W4720); nr Pienaar's R., between Pretoria and Lydenburg, 'Transvaal' (BMNH 220.127.116.11); Lydenburg area, 25 km south, Buffelskloof Nat. Res. (25.3[degrees]S:30.5[degrees]E), 1500 m, indigenous forest, in leaf-litter, D. Plowes (NMSA W6104); Wakkerstroom, 40 km ENE of, Paardeplaats Forest (27.23683[degrees]S:30.50250[degrees]E), 1472 m, indigenous forest, in leaf-litter, J. Horn & M. Lotter, 06/xi/2006 (NMSA W5569). SWAZILAND: Mbabane (26.330[degrees]S:31.133[degrees]E), >1250 m, L.D. Brongersma, 17/x/1938 (cited Bruggen (2004: 46) as Natalina cafra; RMNH.MOL.109689).
Key to taxa in Natalina quekettiana complex 1 Adult shell diameter >35 mm; radula with 6 pairs of lateral teeth per transverse row. Mist-belt and scarp forests of central and south-western Zululand and Kranskop area N. q. lucaris subsp. n. -- Adult shell diameter <35 mm. Mist-belt forests of KZN Midlands and montane forest of Drakensberg escarpment 2 2 Occurring in mist-belt forests of KZN Midlands N. q. quekettiana / N. inhluzana -- Occurring in montane forest of Drakensberg escarpment 3 3 Radula with 7-8 pairs of lateral teeth per transverse row. Central KZN Drakensberg 4 -- Radula with 5 pairs of lateral teeth per transverse row. Along escarpment edge in north-western KZN N. reenenensis 4 Shell of living animal with dark brown apical surface and greenish base. InjasuthiCathkin Peak area N. q. dracomontana subsp. n. -- Shell of living animal relatively pale, more or less uniform greenish brown. Cathedral Peak area N. q. montistempli subsp. n.
Note: In view of the fact that the separation of the subspecies N. q. dracomontana and N. q. montistempli is based primarily on molecular data, and the fact that few living specimens have been collected, the morphological characters given in the key are at best tentative. The distributions given for all taxa within this complex should also be considered provisional.
Natalina quekettiana quekettiana (Melvill & Ponsonby, 1893)
Figs 13C, 35A, F, 36-38
Helix (Macrocyclis) quekettiana: Melvill & Ponsonby, 1893: 103, pl. 3, fig. 1; Moss 1894: 24, pl. 1, fig. 4
radula). Type loc.: Town Bush, Pietermaritzburg [Quekett].
Macrocyclis quekettiana: Sturany 1898: 33.
Rhytida (Afrorhytida) queckettiana [sic]: Mollendorff 1903: 63, pl. 11, fig. 4.
Natalina quekettiana: Melvill & Ponsonby 1898: 170; Connolly 1912: 96; 1939: 107; Watson 1915: 168, 185; 1934: 158, pl. 19, fig. 5; Peile 1932: 103, fig. 2 [deformed radula tooth]; Herbert & Kilburn 2004: 223.
?Helix (Dorcasia) inhluzana Melvill & Ponsonby, 1894: 91, pl. 1, fig. 4. Type loc.: Inhluzan(i) Mountain [Nhlosane], Dargle, KwaZulu-Natal [Mrs Shaw]. See below.
Etymology: Named for Frederick Quekett (1849-1913), first curator of the Natal Society Museum's collections (1886-95) (the precursor of the NMSA) and subsequently curator of the Durban Natural History Museum (1895-1909).
Identification: Very similar to the montane N. q. dracomontana and N. q. montistempli, and at this stage cannot be reliably separated from them morphologically, given that the extent of intra-taxon variation in the latter two taxa is poorly known. May perhaps differ conchologically in that the last whorl is more strongly descendant prior to the aperture, the umbilicus a little wider and the base somewhat smoother in N. q. quekettiana. In addition, the shell periphery often lies below mid-whorl. Frequently resembles N. q. lucaris in shell and body colour, but is smaller and has more numerous lateral teeth in the radula (8-9 pairs per row compared to 6). N. reenenensis also has fewer lateral teeth (5 pairs per row) and is generally paler and greener, though the shells available are all old.
[FIGURE 36 OMITTED]
Description (Fig. 36): Shell generally lenticular, but height of spire somewhat variable; adult shell comprising up to 4.75 whorls, the last usually noticeably descending prior to aperture in adult specimens; whorls rounded, periphery usually slightly below midwhorl, suture a little above mid-whorl; base glossy, apical surface less so. Protoconch 4.5-5.0 mm in diameter, with distinct axial riblets throughout. Apical surface of teleoconch sculptured by close-set axial riblets, these becoming much weaker at periphery and scarcely evident at all on base except around and within umbilicus; base also with traces of spiral striation in some specimens; aperture suboval, somewhat obliquely descending outwards; outer lip of adult frequently thickened basally, but sometimes also retaining a membranous periostracal fringe; adapical portion of outer lip often flattened; upper part of columella lip reflected; umbilicus of moderate width, not obscured to any appreciable degree by reflected columella lip.
Periostracum of living specimens dark chestnut-brown on apical surface (Figs 36H-J), extending a little below periphery to outer region of base, contrasting with lighter yellowish green umbilical and peri-umbilical region; empty shells paler, fading to yellowish brown or light olive-green in older museum material (Figs 36D-G).
Dimensions: Largest specimen (NMSA W6646, Ferncliffe Nat. Res.), diameter 31.3 mm; H:D of adults 0.58-0.68 (N=13).
Living animal (Fig. 35A): Head-foot dark grey-brown to grey-black, lacking paler longitudinal stripes on neck; tentacles similarly dark; skin texture finely granular; posterior portion of foot flat and elongate, tip of tail rather acutely pointed; pedal margin paler, frequently tinged with yellow; skin around genital pore also pale; mantle edge greyish yellow; lung wall variously mottled with dots and anastomosing blotches of black pigmentation, sometimes heavily so; labial palps present.
Radula (Fig. 37): Formula 1+(8-9)+(10-17) (N=7, one in BMNH); length up to 29 mm, with 68-80 broadly V-shaped transverse rows of teeth (see also Moss 1894). The number of marginal teeth in all members of the N. quekettiana complex is lower than in the larger species of Natalina s.s. (<20 vs >20 per half row in adults), although this is probably a function of their smaller size, since juveniles of the larger species have proportionately fewer marginal teeth.
Distal genitalia (Fig. 13C): Epiphallus lumen lined by 3 or 4 longitudinal ridges; interval on inner wall (adjacent to penis) smooth, relatively broad and thin-walled; wall of outer part of epiphallus thicker and the remaining intervals between ridges with numerous, close-set, transverse, slit-like pockets representing openings of diverticulae in thickened epiphallus wall; these strongest in mid to anterior part of epiphallus, but less well defined in posterior third and absent near junction with vas deferens; no epiphallus bulla evident.
Spermatophore: Unknown, but structure of epiphallus wall indicates that, as in N. quekettiana lucaris, it will have a smooth underside and well-developed scale-like spines in the mid to anterior region, on its convex outer surface.
Type material: Three specimens were mentioned in the original description, one in BMNH (1905.1.26.1) was designated lectotype by Connolly (1912: 96), diameter 30.0 mm, height 18.0 mm (Figs 36A-C). The location of the other two specimens is unknown.
Additional material examined (all NMSA unless otherwise indicated): SOUTH AFRICA: KZN: Pietermaritzburg, Ferncliffe Nat. Res. (29.565[degrees]S:30.345[degrees]E), mist-belt Podocarpus forest, in leaf-litter, A. Moussalli, D. Stuart-Fox, D. Herbert & L. Davis, 1/iv/2005 (W4262); ditto (29.54848[degrees]S:30.34481 [degrees]E), mist-belt Podocarpus forest, in leaf-litter accumulations amongst rocks beside path (common), D. Herbert & L. Davis, 16/xii/ 2008 (W6646); ditto (29.555[degrees]S:30.333[degrees]E), mist-belt Podocarpus forest, R. Kilburn, D. Herbert & L. Davis, 12/viii/1994 (V782); Pietermaritzburg, Town Bush (29.565[degrees]S:30.345[degrees]E), A.C. van Bruggen, 09/i/1962 (W3675); ditto (29.565[degrees]S:30.345[degrees]E), mist-belt Podocarpus forest, D. Herbert, xi/1984 (V2149); ditto (29.565[degrees]S:30.345[degrees]E), H.C. Burnup & H.A. Wager, 29/viii/1908 (A7055); ditto (29.565[degrees]S:30.345[degrees]E), (A7054, A7058); Pietermaritzburg, S. slopes of Hogsback Mountain (29.55[degrees]S:30.35[degrees]E), 975-1036 m, beneath rock, C. Griswold & P. Croeser, 20/xi/1984 (V6543); Pietermaritzburg, mist-belt Podocarpus forest, among dead leaves, R. Kilburn & B. Lamoral, 6/x/1969 (V2147); Pietermaritzburg, Boschkop [locality not known], 16/ xii/1921 (A7062); Pietermaritzburg, Hilton Road (29.583[degrees]S:30.330[degrees]E) (A7059); Pietermaritzburg (A7057, 1490); Pietermaritzburg and Hilton, H. Burnup (BMNH 1918.104.22.1688-29); Bulwer area, 3 km to north (29.78160[degrees]S:29.77577[degrees]E), ~1500 m, highly disturbed montane Podocarpus forest beside stream, in leaf litter, A. Moussalli, 06/xii/2003 (W1490).
[FIGURE 37 OMITTED]
Distribution (Fig. 38): Traditionally considered to be endemic to the escarpment northwest of Pietermaritzburg, but a juvenile, identified on the basis of DNA, has recently been collected in the Bulwer area, suggesting a wider distribution in the central KwaZuluNatal Midlands (cf. N. inhluzana); occurs at altitudes of 1000-1500 m.
Habitat: Known only from southern mist-belt forest; in leaf-litter and under logs; very local and generally scarce except in Ferncliffe Nature Reserve, Pietermaritzburg where it is patchily common.
Notes: Connolly (1939) described the shell of Natalina quekettiana as being 'golden brown above and greenish yellow beneath', but whilst this is true of empty shells, particularly older museum specimens, it does not describe the shell coloration of living animals, in which the apical surface is substantially darker brown. In terms of its rather distinctly bicoloured shell, dark head-foot colour, and yellowish mantle and pedal margin, topotypic N. q. quekettiana resembles N. q. lucaris. That subspecies, however, attains a larger size and its radula has only six pairs of lateral teeth per transverse row. In terms of its size, N. q. quekettiana is more similar to the montane taxa in the N. quekettiana complex, but differs from these in that the shell periphery generally lies below mid-whorl, the last whorl is more strongly descendant prior to the aperture, the umbilicus a little wider and the base somewhat smoother. However, given that the montane taxa are all known from relatively few specimens and even fewer adult individuals, the reliability of these characters as species discriminators is not proven. As discussed above, the evidence for these taxa being distinct derives primarily from molecular data. N. reenenensis, for which we have no molecular data, is typically greener, but information on the colour of fresh or living shells is wanting. Its radula possesses only five pairs of lateral teeth per transverse row. We believe that N. inhluzana (Melvill & Ponsonby, 1894) will prove to be a synonym of N. q. quekettiana (see below).
[FIGURE 38 OMITTED]
Conservation: Natalina q. quekettiana was previously thought to occur only in the Pietermaritzburg area, but the data now available indicates that its distribution is more extensive, particularly if N. inhluzana (see below) is indeed a synonym. Nonetheless, given that the indigenous forests of the KwaZulu-Natal Midlands are some of the malacologically most well-known habitats in South Africa, the number of records for both N. q. quekettiana and N. inhluzana is surprisingly small. Despite targeted sampling, very few shells and only one living example have been found in recent years outside the Pietermaritzburg area. Notable is the absence of recent records from forests in the Karkloof region, the most extensive mist-belt forest complex in the KwaZulu-Natal Midlands. At present, the only locality at which the species can be described as common (albeit patchily so) is the Ferncliffe Nature Reserve, north-west of Pietermaritzburg. Whether this is due to a favourable edaphic characteristic of this locality (?doleritic soils) is not known, but it is clear that this municipal reserve should be considered the most important site for the conservation of this snail. As such it should be afforded a high conservation status.
Natalina quekettiana lucaris subsp. n.
Figs 10E, 11C, D, 12C, 14F, 35B, 38-40
Etymology: From Latin lucus (a sacred grove or forest); in reference to the many traditionally sacred sites within the forests of central and southern Zululand, in particular Ngome and Nkandla Forests.
Identification (Fig. 39): For general description see N. q. quekettiana above. Attains a larger size than any of the other taxa in the N. quekettiana complex (adult diameter >35 mm); spire frequently also more elevated and periphery close to mid-whorl; axial riblets usually remaining distinct on base, but not always so; radula with six pairs of lateral teeth per transverse row.
As in N. q. quekettiana, fresh specimens have a darker brown apical surface and frequently a distinctly greenish base, but the contrast fades to a less intense yellowish brown and olive-green with time.
Dimensions: Holotype: diameter 38.4 mm, height 27.1 mm; largest specimen (W1114/ T2562, Nkandla Forest), diameter 43.0 mm; H:D of adults 0.58-0.71 (N=11). Living animal (Fig. 35B): Head-foot dark grey-black dorsally, sides of foot paler; neck region lacking paler, dorsolateral, longitudinal stripes; tentacles dark grey-black; margin of foot fringed with yellow or orange-yellow, mantle edge bright sulphur-yellow to orange; lung wall usually heavily mottled with dots and anastomosing blotches of black pigmentation.
[FIGURE 39 OMITTED]
[FIGURE 40 OMITTED]
Radula (Fig. 40): Like that of Natalina q. quekettiana, but with fewer transverse rows and only six lateral teeth per half row; formula 1+6+(17-20) (N=6, one in BMNH, Piele coll.); length up to 34 mm, with 49-66 broadly V-shaped transverse rows of teeth.
Distal genitalia: As for Natalina q. quekettiana.
Spermatophore (Figs 12C, 14F): Described and illustrated above in discussion of generic characters.
Holotype (Figs 39A-C): SOUTH AFRICA: KZN: Entumeni Nat. Res., (28.88836[degrees]S:31.38007[degrees]E), 620 m, scarp forest, under log, A. Moussalli & D. Stuart-Fox, 24/xii/2003 (NMSA W3310/T2557).
Paratypes: SOUTH AFRICA: KZN: Ngome Forest (27.827[degrees]S:31.415[degrees]E), 1200 m, mist-belt Podocarpus forest, dead under log near camp site, D. Herbert, 19/i/1995 (NMSA V657/T2560, 1 specimen); Ngome Forest, Ntendeka wilderness area (27.80177[degrees]S:31.43765[degrees]E), 1100 m, mist-belt forest, in leaf-litter, A. Moussalli & D. Stuart-Fox, 08/i/2004 (BMNH 20100125, 1 specimen; NMSA W3128/T2566, 3 specimens; W3305/T2559, 5 specimens; W3306/T2564, 2 juvenile specimens); Ngome Forest (27.8281[degrees]S:31.4190[degrees]E), 1110 m, mist-belt section of forest, mostly under logs, D. Herbert, 14/xii/1995 (NMSA V2249/T2563, 6 specimens); Nkandla Forest Res., Chibini area (28.7227[degrees]S:31.1282[degrees]E), 1200 m, mist-belt forest, under logs and in leaf-litter, D. Herbert, M. Bursey & T. Nangammbi, 20/x/2003 (NMSA W1114/T2562, 2 specimens); same data as holotype (NMSA W6854/T2558, 1 specimen; W3317/T2565, 2 juvenile specimens); Entumeni Nat. Res. (28.883[degrees]S:31.383[degrees]E), 700 m, scarp forest, in leaf-litter, O. Bourquin, vii/ 1981 (NMSA B5290/T2561, 1 specimen); Entumeni Nat. Res. (28.88583[degrees]S:31.37944[degrees]E), 663 m, scarp forest, in leaf-litter at base of large tree between forestry office and picnic site, M. & K. Cole, 13/i/2010 (ELM D16217/T027, 1 specimen); Kranskop, Zimbaba Bush (28.9328[degrees]S:30.9510[degrees]E), 1100 m, 1922 (NMSA A7060/T2568, 1 juvenile specimen; A7061/T2567, 2 juvenile specimens; A7135/T2569, 1 specimen).
Distribution (Fig. 38): Known primarily from the interior of Zululand (Ngome, Nkandla and Entumeni forests), but extending across the Thukela River valley to the Kranskop area; occurs at altitudes of 600-1200 m.
Habitat: Restricted to Afrotemperate and scarp forest; in leaf-litter and under logs; evidently scarce.
Notes: Molecular data indicate this subspecies to be the sister taxon of the nominotypical subspecies (Moussalli et al. 2009), which it resembles in terms of the bicoloured shell pattern in living specimens and the very dark head-foot coloration. It differs in attaining a considerably larger size and in having only six lateral teeth per half row in the radula, compared to 8 or 9 in N. q. quekettiana.
Some variation in coloration, possibly geographical, is evident. Specimens from Ngome Forest have a distinctly bicoloured shell with a dark brown apical surface, whereas in those from Entumeni Forest the shell is less strongly bicoloured, with a chestnut to tan apical surface, and the mantle edge and pedal margin are orangish rather than bright yellow.
Conservation: The known extent of occurrence of N. q. lucaris is approx. 2500 km2, but within this range its distribution is limited to islands of mist-belt and scarp forest. The forests from which it has been recorded include some of the largest such habitats remaining in KwaZulu-Natal (>2750 ha), and it is likely also to occur in Qudeni Forest, another large but very poorly sampled forest. These forests are in some cases formally protected, but the level of protection is variable and its efficacy is not guaranteed. Owing to their remote location in underdeveloped areas, the forests are subject to on-going anthropogenic pressure in the form of subsistence harvesting of forest products, grazing and trampling by livestock, and peripheral encroachment by small-scale agriculture.
Natalina quekettiana dracomontana subsp. n.
Figs 35C, D, 41-43
Etymology: From Latin draco (a dragon) and mons (a mountain); in reference to the Drakensberg.
Identification (Fig. 41): For general description see Natalina q. quekettiana above. The limited material available indicates this subspecies to vary considerably in shell proportions and colour, but there appear to be no clear-cut morphological characters that serve to reliably distinguish it from other subspecies within the N. quekettiana complex, except N. q. lucaris and N. reenenesis which have fewer pairs of lateral teeth per transverse row in the radula (but see also observations on epiphallus).
[FIGURE 41 OMITTED]
Dimensions: Holotype: diameter 27.2 mm, height 19.5 mm; largest specimen (NMSA W4093/T2453, Monks Cowl), diameter 30.2 mm; H:D including some slightly subadult specimens 0.55-0.72 (N=5) (0.55 in single available adult).
Living animal (information available for only two animals) (Figs 35C, D): Dorsal region of head-foot dark grey-brown to charcoal-grey, lacking paler longitudinal stripes on neck; tentacles of similar colour; sides of foot paler; mantle edge pale buff-brown or yellow, if yellow then pedal margin also yellow (Fig. 35D); lung wall without large black blotches, pigmentation mostly fine and tracking blood vessels, particularly to right of pulmonary vein.
Radula (Fig. 42): Formula 1+(7-8)+(12-19) (N=2); length up to 28.5 mm, with up to 70 V-shaped rows of teeth.
Distal genitalia: Epiphallus like that of N. q. quekettiana, but in both of the two mature specimens available there was a small bulla on the outer side of the epiphallus, just above its junction with the vas deferens. Internally the bulla possessed a short diverticulum of the main epiphallus lumen, suggesting that the spermatophore may possess a thumb-like or finger-like process on the tail region (cf. N. beyrichi and N. cafra eumacta). Spermatophore: Unknown, but epiphallus structure suggests that as in other subspecies of N. quekettiana, the anterior two-thirds will bear well-developed scale-like spines. The possibility of an additional process on the tail (see previous paragraph), however, is something not so far evident in other subspecies within this complex.
Holotype (Figs 41A-C): SOUTH AFRICA: KZN: Injasuthi, central Drakensberg, (29.1417[degrees]S:29.4250[degrees]E), 1600 m, montane Podocarpus forest, in leaf-litter, D. Herbert, M. Seddon & P. Tattersfield, 8/xii/1998 (NMSA V7992/T2451).
Paratypes: SOUTH AFRICA: KZN: Monk's Cowl area, forest below Sterkspruit Falls (29.03762[degrees]S:
29.40632[degrees]E), altitude 1350 m, montane Podocarpus forest, in leaf-litter, D. Herbert, Earthwatch, 15/iii/ 2006 (NMSA W4093/T2453, 2 specimens); ditto, forest below Sterkspruit Falls (29.03414[degrees]S:29.40685[degrees]E), 1420 m, montane Podocarpus forest, in leaf-litter, D. Herbert, Earthwatch, 15/iii/2006 (NMSA W4101/ T2452, 1 specimen); Cathkin Peak area (29.037[degrees]S:29.388[degrees]E), Falcon coll'n (NMSA A7056/T2454, 3 specimens).
[FIGURE 42 OMITTED]
Other material examined: SOUTH AFRICA: KZN: Monk's Cowl area (29.03707[degrees]S:29.38753[degrees]E), 1650 m, indigenous forest, in leaf-litter, M. Hamer et al., 09/iv/2006 (NMSA W5097).
Distribution (Fig. 43): Confirmed records only from the Mdedelelo [Cathkin Peak] and Injasuthi areas in the central KwaZulu-Natal Drakensberg; occurs at altitudes of 1350-1650 m.
Habitat: Afrotemperate forest, in leaf-litter; evidently rare.
Notes: We describe this as a new taxon primarily on the grounds of molecular data (Moussalli et al. 2009) which indicate it to represent a distinct lineage that is sister to the clade comprising N. q. quekettiana and N. q. lucaris. It shares with these taxa the distinctive bicoloured shell (living and fresh shells only), and in some individuals, the yellow mantle edge and pedal margin. Nearly all the material available is subadult and the aperture thus perhaps less oblique (more circular) than it would be at adulthood. In addition, there is also an indication of a difference in epiphallus structure, namely the presence of an epiphallus bulla, but this observation is based on only two specimens. Given that this character appears variable in N. c. eumacta and N. c. natalensis, its taxonomic significance must be interpreted with caution.
Conservation: The distribution of N. q. dracomontana is evidently somewhat greater than that of N. q. montistempli, but the available records suggest that its range is nonetheless very limited. It occurs in a formally conserved region (the uKhahlamba Drakensberg World Heritage Site), where disturbance is low and thus its habitat is afforded a high degree of protection. On-going management practices, however, need to ensure that the integrity of forest patches within the broader mosaic of Drakensberg ecosystems is maintained. Uncontrolled fires in the neighbouring grasslands are likely to represent the most significant threat.
[FIGURE 43 OMITTED]
Natalina quekettiana montistempli subsp. n.
Figs 35E, 43-45
Etymology: From Latin mons (a mountain) and templum (a temple); with reference to Cathedral Peak.
Identification (Fig. 44): For general description see Natalina q. quekettiana above. Although limited material is available it is evident that the shell of the living animal is paler and more uniformly coloured than in any of the other subspecies discussed above. The distinctive bicoloured pattern present in fresh, live-collected shells of the other subspecies is not evident in N. q. montistempli, in which the apical and basal surfaces are more or less the same colour even in fresh, live-collected shells (Figs 44A-C). In terms of the pale shell colour it resembles N. reenenensis, but in that taxon the radula has only five lateral teeth per half row, compared to eight in N. q. montistempli (acknowledging that for both taxa details of radula dentition are known for very few specimens).
Dimensions: Holotype (largest specimen), diameter 28.0 mm, height 14.4 mm; H:D of adults 0.51-0.62 (N=9).
Living animal (information available for only one animal) (Fig. 35E): Dorsal region of head-foot dark grey, lacking paler longitudinal stripes on neck; tentacles somewhat darker; sides of foot progressively paler toward pedal margin, the latter not distinctively coloured, whitish beneath shell; mantle edge very pale, almost white; lung wall with some rather diffuse black pigmentation, particularly associated with blood vessels, but not heavily blotched.
Radula (Fig. 45): Formula 1+8+(14-18) (N=4); length up to 20.4 mm, with up to 71 broadly V-shaped rows of teeth.
Distal genitalia: Epiphallus structure typical of N. quekettiana; a bulla is not evident. Spermatophore: Unknown. Epiphallus structure suggests that the anterior two-thirds will bear well-developed scale-like spines.
[FIGURE 44 OMITTED]
[FIGURE 45 OMITTED]
Holotype (Figs 44A-C): SOUTH AFRICA: KZN: Fern Forest (Oqalweni Forest), Cathedral Peak area, (28.94329[degrees]S:29.18580[degrees]E), 1531 m, montane Podocarpus forest, in leaf-litter, D. Herbert, Earthwatch, 19/ iii/2006 (NMSA W4084/T2422).
Paratypes: SOUTH AFRICA: KZN: same data as holotype (NMSA W6653/T2428, 4 adults and 3 juveniles; W5095/T2449, 1 specimen); Cathedral Peak area, Oqalweni Forest (28.94265[degrees]S:29.18941[degrees]E), 1552 m, indigenous forest, in leaf-litter, M. Hamer et al, 19/iii/2006 (NMSA W5093/T2448, 1 specimen); ditto, Oqalweni Forest (28.9422[degrees]S:29.1814[degrees]E), 1600 m, montane Podocarpus forest, in leaf-litter, A.C. & W.H. van Bruggen, 05/iv/1962 (NMSA B0044/T2447, 1 specimen); ditto, Rainbow Gorge (28.95813[degrees]S: 29.22070[degrees]E), 1550 m, montane Podocarpus forest, in leaf-litter, C. Uys, 06/i/2005 (NMSA W2605/T2446, 1 specimen; W4596/T2430, 4 specimens); ditto, Rainbow Gorge (28.96051[degrees]S:29.22455[degrees]E), 1518 m, indigenous forest, in leaf-litter, M. Hamer et al., 12/iii/2006 (NMSA W5091/T2445, 2 specimens, crop contents included partially digested earthworms, Proandricus sp); ditto, Rainbow Gorge (28.96012[degrees]S: 29.22520[degrees]E), 1600 m, montane Podocarpus forest, in leaf-litter, C. Uys, 05/i/2005 (NMSA W2591/T2444, 1 specimen); ditto, Ndumeni Forest (28.961 [degrees]S:29.222[degrees]E), 1550 m, under logs and rocks, C. Griswold, 22/ii/ 1984 (NMSA V7745/T2432, 1 specimen); ditto, Ndumeni Forest (28.961[degrees]S:29.224[degrees]E), 1550 m, under stone at foot of krantzes, A.C. & W.H. van Bruggen, 03/iv/1962 (NMSA V5205/T2431, 1 specimen); Cathedral Peak area, 1540 m, montane Podocarpus forest, R. Kilburn, 21/i/1984 (NMSA V2148/T2429, 1 specimen).
Distribution (Fig. 43): Known only from the Cathedral Peak area in the KZN Drakensberg; occurs at altitudes of 1500-1600 m.
Habitat: Afrotemperate forest, in leaf-litter.
Notes: As with Natalina q. dracomontana, we describe this material as a new taxon largely on account of molecular data (Moussalli et al. 2009) which indicate it to comprise a deeply divergent lineage within the N. quekettiana complex. However, although few adult specimens are available, there is also some evidence that the shell coloration is also distinctive.
This occurrence of a distinctive lineage of land snail in the Cathedral Peak area is mirrored by two achatinid species Cochlitoma montistempli (Bruggen, 1965) and C. omissa (Bruggen, 1965). It strongly suggests that this region of the Drakensberg has been subject to historical environmental conditions that have resulted in the long-term isolation and independent evolution of a distinctive and perhaps now relictual fauna of narrow-range endemics. Similar narrow-range endemism is found in the chameleon fauna of the Drakensberg (Tolley & Burger 2007) (see also biogeographic summary below).
Conservation: On account of its very limited distribution (known extent of occurrence is less than 3.0 km2) Natalina q. montistempli is clearly a taxon of conservation concern. It occurs in a formally protected region (the uKhahlamba Drakensberg World Heritage Site) where disturbance is limited, but it is evident that the forests of the Cathedral Peak area harbour a fauna of particular interest and that they should be managed so as to keep disturbance to a minimum. Burning practices in the surrounding grasslands need to be particularly carefully managed.
Natalina inhluzana (Melvill & Ponsonby, 1894)
Figs 38, 46
Helix (Dorcasia) inhluzana: Melvill & Ponsonby 1894: 91, pl. 1, fig. 4. Type loc.: Inhluzan(i) Mountain
[Nhlosane], Dargle, KwaZulu-Natal [Mrs Shaw].
Dorcasia inhluzana: Melvill & Ponsonby 1895: 165, pl. 12, fig. 6; Sturany 1898: 50.
Rhytida (Afrorhytida) inhluziana [sic]: Mollendorff 1903: 64, pl. 11, fig. 7.
Rhytida inhluzana: Melvill & Ponsonby 1907: 99.
Natalina inhluzana: Connolly 1912: 94; 1939: 109; Watson 1934: 158; Herbert & Kilburn 2004: 223.
Etymology: Named after Inhluzan(i) Mountain [Nhlosane], Dargle, KwaZulu-Natal, South Africa.
Identification: Very similar to Natalina q. quekettiana, differs only in being smaller (but has fewer whorls, 4.0-4.5 compared to 4.5-5.0) and in having slightly weaker axial sculpture on the apical surface. Largest specimen (lectotype), diameter 23.0 mm; H:D of adults 0.61-0.64 (N=4).
Radula and soft parts: Unknown.
Type material: Two specimens were mentioned in the original description, one in BMNH (1922.214.171.124) was designated lectotype by Connolly (1912: 94), diameter 23.0 mm, height 15.0 mm (Fig. 46). The paralectotype is in NMSA (2853/T592), diameter 22.4 mm, height 13.9 mm.
Additional material examined: SOUTH AFRICA: KZN: Inhluzana [Nhlosane] Mtn (29.55[degrees]S:29.93[degrees]E) (NMSA A7063, A7064, juveniles); Fort Nottingham, Tony Ker trail (29.41106[degrees]S:29.91512[degrees]E), 1575 m, mist-belt Podocarpus forest, D. Herbert & L. Davis, station 08-064, 18/xii/2008 (NMSA W6640); Karkloof, H. Burnup Coll'n (NMSA B0022).
Distribution (Fig. 38): Known only from the Nhlosane-Fort Nottingham region in the KwaZulu-Natal Midlands, and perhaps also the Karkloof area.
Habitat: Not specifically stated in original description or on specimen labels, but presumably mist-belt forest.
Notes: It seems probable that N. inhluzana is a synonym of N. quekettiana quekettiana. Although the type specimens of N. inhluzana have weaker axial sculpture than is typical of N. q. quekettiana from Pietermaritzburg, in other respects they very much resemble subadult specimens of the latter with 4.0-4.5 rather than 4.5-5.0 whorls. It is puzzling that neither Melvill and Ponsonby (1984) nor Connolly (1939) offered any comparison between N. inhluzana and N. quekettiana, particularly considering the relative proximity of their type localities (approx. 40 km apart). Fresh material and DNA sequence data are needed before a more conclusive assessment of the validity of this taxon can be made. However, despite repeated attempts to obtain living material from the type locality, none has been found. The remaining forest habitats on the Nhlosane Mountain and its southerly spur are now of very limited extent and considerably degraded as a result of alien plant invasion, trampling by cattle and subsistence harvesting of forest products. It is likely that the species is now extinct at the type locality, but attempts to find it in more well-preserved and more extensive forest fragments in the broader DargleNottingham Road area are on-going.
[FIGURE 46 OMITTED]
Somewhat worn shells closely resembling the holotype are present in the Natal Museum, with the locality given simply as 'Karkloof'. Although the Karkloof area is extensive and the locality data thus imprecise, it suggests that the species may occur more widely in this part of the central KwaZulu-Natal Midlands. Likewise, molecular data from an otherwise indeterminate juvenile from Bulwer (Moussalli et al. 2009) revealed it to be close to N. quekettiana from the type locality (see above), suggesting that this too is more widely distributed in the central KwaZulu-Natal Midlands than was previously thought. The possibility that there is a single species, varying somewhat in size and strength of sculpture, occurring in the mist-belt and lower altitude montane Podocarpus forests of the central KwaZulu-Natal Midlands seems likely.
Conservation: If genuinely a distinct species, Natalina inhluzana would undoubtedly qualify for ranking as a threatened species. However, since there is insufficient data on the taxonomic validity of the species, an evaluation of its threat status cannot be made at present (but see comments concerning N. q. quekettiana above).
Natalina reenenensis Connolly, 1939
Figs 43, 47
Natalinareenenensis: Connolly 1939: 108, pl. 2, figs 5-8. Type loc.: Van Reenen, KwaZulu-Natal [Burnup]; Herbert & Kilburn 2004: 223.
Etymology: Named after the type locality, Van Reenen, KwaZulu-Natal, South Africa.
Identification: Closely resembles subspecies within the Natalina quekettiana complex; attains a slightly larger size than all except N. q. lucaris; typically has a relatively low profile (H:D<0.60), a more narrowly entering umbilicus and the radula has fewer lateral teeth per transverse row (five pairs).
Description (Fig. 47): Shell lenticular, spire generally low; adult shell comprising up to 4.5 whorls, the last descending slightly prior to aperture in adults; periphery evenly rounded, at or near mid-whorl; suture above mid-whorl; apical surface microscopically sculptured by extremely fine spiral lineation, producing lustreless, silky sheen which continues on to base, only becoming glossy near umbilicus. Protoconch/teleoconch junction generally ill-defined; protoconch [+ or -]5.0 mm in diameter, apical portion initially almost smooth, becoming plicate at suture and thereafter with distinct, close-set, axial riblets extending from suture to suture. Axial riblets continue on teleoconch but become more uneven on last half whorl; riblets weaken at periphery, the base generally sculptured only by growth-lines and traces of spiral striae; riblets re-appear in umbilicus; aperture suboval, slightly obliquely descending outwards; outer lip of adult a little thickened, particularly where columella and basal lips merge, but sometimes throughout in gerontic specimens, thin and with membranous periostracal fringe in subadults; upper part of columella lip weakly reflected; umbilicus of moderate width, but narrowing relatively quickly internally, not obscured by reflected columella lip.
Periostracum of museum specimens straw-yellow to light olive-green with darker axial bands in a slightly deeper shade; base not appreciably paler than apical surface. One fresher, but damaged shell recently collected near type locality with a distinctly browner coloration.
Dimensions: Largest specimen (NMSA W4689), diameter 32.4 mm; H:D of adults 0.53-0.59 (N=11).
Living animal: No data available.
Radula: Like that of N. quekettiana, but with fewer lateral teeth; formula 1+5+?16 (radula slide prepared by A.J. Peile in NMSA); length 22.3 mm, with 69 broadly Vshaped rows of teeth. Another radula slide in BMNH (Gwatkin) has the same formula.
Type material: Holotype in BMNH (19126.96.36.1997-8) [2 specimens, holotype undamaged and with red dot], diameter 30.3 mm (31 mm fide Connolly 1939), height 17.5 mm (Figs 47A-C); paratypes in NMSA, same data as holotype, dated iii/1918 (V2010/T1356, 8 specimens; V2009/T1355, 3 specimens).
Additional material examined: SOUTH AFRICA: KZN: De Beers farm, approx. 15 km NE of Van Reenen (28.30403[degrees]S:29.50240[degrees]E), 1841 m, afrotemperate forest, dead in leaf-litter, A. Moussalli, D. Stuart-Fox & M. Cunningham, 10/ix/2006 (NMSA W4689).
Distribution (Fig. 43): Known only from the Drakensberg escarpment in the Van Reenen area, north-western KwaZulu-Natal.
Habitat: No details recorded with original specimens, but presumably found in Afrotemperate forest, ca 1500-1800 m; evidently scarce.
[FIGURE 47 OMITTED]
Notes: In the original description, Connolly (1939) compared this species with Natalina kraussi (now in Afrorhytida) noting that it was larger and of a much greener colour. Surprisingly, he did not compare his new taxon with N. quekettiana, with which it is much more similar. In reality the material available, even though old and thus faded, is not noticeably greener than some specimens of N. quekettiana of a similar age. The fading of shells which may be rich chestnut-brown when alive to a paler olive-green with advancing time seems a general phenomenon in these snails. Even though Connolly's original description mentioned the green colour, an old label in paratype lot NMSAV2009/T1355 states 'live, Mar. 1918'. The shells were thus already around 20 years old when Connolly drew up the description. The green colour must thus be viewed with caution, for it is neither distinctive of dead shells of the species, nor is it likely to reflect shell colour in the living animal. A badly broken but recently collected shell was of a much browner hue.
Natalina reenenensis almost certainly belongs within the N. quekettiana clade, but DNA sequence data are needed to confirm this. Although little material is available, the species seems to differ in having a relatively narrow, slightly eccentric umbilicus and the lustreless sheen of the apical surface extends well below the periphery, and only the peri-umbilical region is glossy. In Natalina q. quekettiana the periphery is often less evenly rounded and displaced slightly towards the base, the spire usually taller (H:D 0.58-0.68 compared with <0.60), and the umbilicus is noticeably wider. Natalina q. montistempli is perhaps the most similar taxon, but like all the other subspecies of N. quekettiana, it has more than five pairs of lateral teeth per transverse row. More definitive comment on this species must await the collection of additional living specimens.
Distribution data suggest the existence of a genuine hiatus between the populations of N. reenenensis and those of the geographically closest subspecies in the N. quekettiana complex, N. q. montistempli. Despite extensive sampling in the intervening forests of the Royal Natal National Park (Bruggen, Hamer, Herbert and Moussalli), no Natalina specimens have been found there.
Conservation: Natalina reenenensis is evidently both rare and of limited distribution. Only one damaged shell has been found since the original description. The original sample collected by Henry Burnup evidently contained over a dozen live-taken specimens, suggesting that the species was common, but this was perhaps a very local phenomenon. With a known distribution including only two localities and covering only a 15 km length of the escarpment edge in north-western KwaZulu-Natal, the species would certainly qualify for listing as a threatened species. The extent of its habitat has declined historically and its quality remains threatened, particularly by veld fires encroaching from the neighbouring grasslands. However, this region of the Drakensberg escarpment is not well-sampled and a more meaningful assessment of the conservation status of N. reenenensis must await further survey work.
Subgenus Tongalina subgen. n.
Type species: Helix cafra wesseliana Kobelt, 1876.
Etymology: With reference to Tongaland, the territory historically encompassing southern Mozambique and northern KwaZulu-Natal.
Diagnosis: Skin texture in neck region coarse; genital pore situated high on neck and well posterior to right optic tentacle; left body lobe of mantle hypertrophied, divided into two lobes, but these confluent, separated only by a sinuous discontinuity.
Notes: Natalina (Tongalina) is monotypic, the only known species being N. wesseliana. In terms of shell morphology it is very close to the larger species of Natalina s.s. and indeed N. wesseliana was initially described merely as a variety of N. cafra. Several character states of the soft parts (see diagnosis), however, differ markedly from those found in Natalina s.s. indicating not only that it is a distinct species, but that it represents a highly divergent lineage of its own. This is supported by molecular data which place it as a basally divergent taxon within Natalina.
Natalina (Tongalina) wesseliana occurs at low altitudes (<700 m) in north-eastern KwaZulu-Natal and southern Mozambique. The distributional data available to date indicate that its range does not overlap with any other species of Natalina.
Natalina (Tongalina) wesseliana (Kobelt, 1876)
Figs 6D, 10F, 11E, F, 48-52
Helix cafra var. wesseliana: Kobelt 1876: 149, pl. 5, fig. 1; Pfeiffer 1877: 558. Type loc.: not originally specified, but given as 'South Africa (fide Kobelt)' by Connolly (1939); label with holotype states 'Natal'.
Aerope caffra [sic] var. wesselliana [sic]: Tryon 1885: 131, pl. 25, fig. 14.
Natalina caffra [sic] var. wesseliana: Melvill & Ponsonby 1898: 170; Sturany 1898: 30; Mollendorff 1903: 21, pl. 3, fig. 8; Connolly 1912: 91.
Natalina wesseliana: Connolly 1925: 122; 1939: 107; Bruggen 1969: 58; Herbert & Kilburn 2004: 221.
Natalina (Natalina) wesseliana: Bruggen & Appleton 1977: 32.
Etymology: Perhaps named in honour of Marthinus Wessel Pretorius (1819-1901), president of the Transvaal Republic and the Orange Free State.
[FIGURE 48 OMITTED]
[FIGURE 49 OMITTED]
Identification: Shell characterised by its narrow umbilicus which is largely obscured by the reflected columella, and the rapidly expanding, somewhat auriform shell. May possibly be confused with N. cafra natalensis especially when juvenile, but the coarse skin texture of the neck of N. wesseliana and the position of its genital pore are distinctive, as is its northern, low altitude distribution.
Description (Fig. 48): Shell large to very large, thin and fragile; last adult whorl expanding rapidly and suture descending slightly towards aperture; sculptured by close-set axial riblets which sometimes extend on to base; protoconch diameter 7.0-8.5 mm, the axial riblets generally finer and more close set than in Natalina s.s.; umbilicus narrow, for the most part obscured by reflected columella lip; aperture ovate, large and drooping obliquely downwards (long axis of aperture strongly oblique); outer lip thin, membranous periostracal fringe well developed.
Periostracum olive-green to olive-brown with occasional darker radial bands, particularly just behind outer lip.
Dimensions: Largest specimen (NMSA 2118, 'Zululand'), diameter 69.0 mm. H:D of adults 0.70-0.88 (N=9).
Living animal (Fig. 49A): Head-foot brownish, tinged with orange at pedal margin; mantle edge hypertrophied, the left body lobe comprising two contiguous lobes separated by a sinuous discontinuity (Fig. 6D), orange; skin of neck region very coarsely textured with roundly conical projections, each often with a small pit in the centre; posterior region of foot extensive, flattened and pointed; genital pore situated high on neck, well posterior to right optic tentacle (Fig. 49B); lung wall variably marked with black pigmentation, usually with some diffuse spiral bands.
Radula (Fig. 50): Like that of Natalina s.s. species; formula 1+5+>20 (N=2); length up to 46 mm (but almost certainly longer in large specimens), with 56-60 broadly Vshaped transverse rows of teeth.
Distal genitalia: Essentially the same as in Natalina s. s. species, except for the position of the genital pore. The penis and epiphallus are strongly sinuous in situ and the papillation of wall of penis lumen has a zig-zag longitudinal orientation. Interior of epiphallus with 6-7 well-developed longitudinal ridges with finer second and third order intermediary ridges. A small bulla is evident on the epiphallus, close to its junction with the vas deferens.
[FIGURE 50 OMITTED]
Spermatophore (Fig. 51): Well preserved allospermatophores from the oviduct caecum of two specimens have been examined (NMSA V7668, W5719) collected in late November and late December respectively. These resemble the spermatophores of the larger Natalina s. s. species in bearing keel-like longitudinal ridges and lacking spines. One spermatophore was particularly long (straightened length approx. 32 mm) and slender (Fig. 51B), with a pronounced spiral twist; the other one similar but somewhat less slender and not strongly twisted, though still distinctly curved. Spermatophore of more or less uniform width for most of its length, tapering at both ends; 4 or 5 major longitudinal ridges anteriorly, increasing to 6 or 7 in mid region, with occasional weaker intermediaries; crests of major ridges themselves usually appearing bifid. Near spermatophore head, inner surface of spiral bears a deep groove, which becomes progressively broader and more shallow toward mid region, ending at subterminal vent. In one specimen, posterior portion of spermatophore asymmetrically T-shaped and obliquely twisted relative to main shaft of spermatophore (Fig. 51C); vent situated at T-junction and extending into arms, one of which comprises the strongly recurved tip of the tail and the other a shorter, less strongly recurved thumb-like process. This posterior spermatophore morphology also evident in the other example, but thumb-like process only weakly developed.
In situ, the spermatophore head lay pressed against the extreme end of the oviduct caecum and the posterior portion was situated such that the recurved tail extended into the base of bursa copulatrix duct and the thumb-like process into the vagina. In this position the vent lay immediately beneath the end of the free oviduct, and it seems likely that the function of these posterior processes is to anchor the spermatophore in place, once it is in the correct position.
Unusually, in specimen NMSA W5719 the caecum was distended and sack-like and contained two spermatophores, one relatively fresh (situated as described above) and the other partially degraded. In a third specimen (NMSA V7668) the caecum contained three more extensively degraded spermatophores, each compacted into an oval mass.
[FIGURE 51 OMITTED]
Type material: Holotype of Helix cafra var. wesseliana Kobelt, 1876 (Figs 48A-C) in Senckenberg Museum (SMFD 8287), Natal, coll. Kobelt, ex Maltzan, 1878, diameter 46.0 mm, height 40.5 mm (fide Ronald Janssen).
Additional material examined (all NMSA unless otherwise indicated): MOZAMBIQUE: Praia do Xai-Xai camping grounds (25.11324[degrees]S:33.74019[degrees]E), 24 m, dune forest, in leaf-litter, A. Moussalli & D. Stuart- Fox, 27/xii/2006 (L7364); Maputo area, environs of Lagoa Ricatla [Rikatla] (25.767[degrees]S:32.617[degrees]E), H. Junod (BMNH 19188.8.131.520-31); Ponta do Ouro (26.833[degrees]S:32.892[degrees]E), dune forest, in leaf-litter, M. Evans, x/ 2006 (L7491). SOUTH AFRICA: KZN: Kosi Bay (26.958[degrees]S:32.833[degrees]E), F. Toppin, 1906 (B0020); ditto (SAMC A34748); Kosi Bay (26.86922[degrees]S:32.88258[degrees]E), coastal dune forest, transect E, Symes, Lovell & Combrink, 21/x/2003 (W1430); Bhanga Neck (27.005[degrees]S:32.863[degrees]E), O. Bourquin, i/1965 (B0077); Bhanga Neck, behind visitors quarters (27.005[degrees]S:32.863[degrees]E), coastal dune thicket, R. Fregona, 12/vii/1987 (D9888); Lebombo Mts, Hlatikulu Nat. Res. (27.32466[degrees]S:31.98981[degrees]E), 647 m, scarp forest, in leaf-litter, A. Moussalli & D. Stuart-Fox, 29/xii/2007 (W5719); ditto (27.32622[degrees]S:31.99813[degrees]E), scarp forest, A. Moussalli & D. Stuart-Fox, 19/v/2003 (W4831); Mkhuze Game Res. [station MAxC], Acacia xanthophloea grove beside Msunduzi River (27.74705[degrees]S:32.28982[degrees]E), dead amongst plant debris around tree trunks [perhaps flood borne], Earthwatch Team 5, 23/xi/2003 (W1326); Makowe (27.967[degrees]S:32.117[degrees]E), J. Crosly (1489); Hluhluwe Game Res. (28.075[degrees]S:32.055[degrees]E), 400 m, scarp forest, in leaf-litter, Herbert, Seddon & Tattersfield, 30/xi/ 1998 (V7668); ditto, (28.077[degrees]S:32.045[degrees]E), 460 m, scarp forest, in leaf-litter, Herbert, Seddon & Tattersfield, 29/xi/1998 (V7684); ditto, Hilltops Camp walk (28.0830[degrees]S:32.0417[degrees]E), 400 m, scarp forest, D. Herbert, 01/vii/1996 (V3820); ditto, in forest between research station and perimeter fence (28.097[degrees]S:32.067[degrees]E), 460 m, scarp forest, in leaf-litter, D. Herbert, 15/i/1995 (V0573); St Lucia system: False Bay Park (27.95852[degrees]S: 32.35919[degrees]E), sand forest, in leaf-litter and under logs, Earthwatch Team 9, 15/i/2005 (W3060); ditto (27.96460[degrees]S:32.37869[degrees]E), closed woodland/forest on fossiliferous sediments beside lake, in leaf-litter and under logs, Earthwatch Team 8, 05/xi/2004 (W2447); ditto (27.969750[degrees]S:32.372615[degrees]E), sand forest, under dead log in leaf-litter, A. Armstrong et al., 06/iii/2001 (V9188); ditto, Mpophomeni Trail (27.975[degrees]S:32.358[degrees]E), 30 m, woodland thicket and sand forest, D. Herbert, 03/i/1996 (V2166); Cape Vidal, Bhangazi Hill (28.123[degrees]S:32.555[degrees]E), 60-80 m, dune forest, in leaf-litter, specimen found eating Cochlitomavestita, Herbert, Seddon & Tattersfield, 27/xi/1998 (V7976, V7980); ditto (28.130[degrees]S:32.547[degrees]E), 60-80 m, dune forest, in leaf-litter, Herbert, Seddon & Tattersfield, 27/xi/1998 (V7943); Eastern Shores forest walk (28.23[degrees]S:32.49[degrees]E), coastal lowland forest, under log, D. Herbert, 19/x/1997 (V5381). SWAZILAND: Ingwavuma Road (27.083[degrees]S:31.967[degrees]E), 275-370 m, A.C. & W.H. van Bruggen, 01/xi/1964 (B0096).
Observation records: SOUTH AFRICA: KZN: Sodwana Bay, forest beside Lake Mgobezeleni (27.53833[degrees]S: 32.66670[degrees]E), coastal forest, D. Herbert, 07/ii/2004; Cape Vidal, NPB camp site (28.13[degrees]S:32.55[degrees]E), [+ or -]20 m, dune forest and Casuarina mosaic, found crawling on track after rain, D. Herbert, 18/x/1997.
Additional literature records (material not seen): MOZAMBIQUE: Marracuene [Vila Luiza] (25.7369[degrees]S: 32.6764[degrees]E), P.H. Boshoff (Bruggen 1967: 28, specimen damaged, identification tentative, Bruggen in lit. v/2008). SOUTH AFRICA: KZN: Lake Sibaya environs (27.400[degrees]S:32.733[degrees]E), Appleton (Bruggen & Appleton 1977).
Distribution (Fig. 52): Central Zululand (Hluhluwe and Cape Vidal) north to the Limpopo R. in southern Mozambique (Xai-Xai), mostly near the coast. To date not recorded further inland than Hluhluwe Game Reserve and the Lebombo Mountains on the Maputaland-Swaziland border, reaching 650 m above sea level, but there are unconfirmed records of large Natalina specimens from Mpumalanga (Nelspruit) which may belong to this species (Sirgel pers. comm.).
Habitat: Recorded from dune, coastal lowland and scarp forest, but may also occur in other well-wooded habitats; in leaf-litter and under logs; locally common. All localities lie within either the Indian Ocean Coastal Belt or the Lowveld Savannah bioregions of Mucina and Rutherford (2006).
Notes: The somewhat auriform and narrowly umbilicate shell of Natalina wesseliana is distinctive. It is currently known only to the north of the Mfolozi R. and is the only Natalina species so far know from altitudes of less than 1000 m lying north of this river. The living animal is spectacular and the very coarse texture of the skin in the neck region is conspicuous. When actively crawling the animal is reluctant to retreat into its shell. It has been found feeding on Cochlitoma vestita (Pfeiffer, 1855) (Achatinidae) and a large individual was found with a specimen of the carnivorous slug Chlamydephorus gibbonsi Binney, 1879 (Chlamydephoridae) in its crop. The latter was cut into three almost completely detached fragments, which, given the considerable thickness and rigidity of the skin of chlamydephorid slugs, attests to the efficacy of the radula of large Natalina species.
[FIGURE 52 OMITTED]
Conservation: Listed as Vulnerable [B1+2bc] (IUCN 2010) on account of its limited distribution and the on-going threats to coastal forest habitats in south-east Africa. Fortunately, many of the South African localities at which it is known to occur are situated in formally protected areas, namely the iSimangaliso Wetland Park (World Heritage Site, formerly Greater St Lucia Wetland Park) and Hluhluwe Game Res., where it is not uncommon in dune and scarp forest habitats. However, north of Maputo in Mozambique, much of the indigenous vegetation in the coastal hinterland has been lost and only isolated fragments remain.
Genus Afrorhytida Mollendorff, 1903
Afrorhytida: Mollendorff 1903: 61. Type species: Helix knysnaensis Pfeiffer, 1846, by original designation.
Hyperrhytida Watson, 1934: 156. Type species: Helix (Aerope) trimeni Melvill & Ponsonby, 1892, by original designation.
Diagnosis: Shell of moderate size (adult diameter up to 31 mm), lenticular to globose, more or less uniformly yellowish or greenish brown, or brown, lacking spiral colour pattern; apical surface sculptured with close-set axial riblets, base smoother and more glossy; outer lip slightly thickened and without periostracal fringe; peristome interrupted in parietal region; umbilicus open, width narrow to moderate; protoconch of approx. 1.25 whorls, sculptured by axial riblets (sometimes weak), diameter 2.5-5.0 mm. Radula possessing rachidian tooth; outer lateral teeth conspicuously larger than marginal teeth; inner marginal teeth small but not vestigial. Labial palps present, but relatively small; left body lobe of mantle divided into two lobes, separated by a low ridge. Penis elongate and cylindrical, situated to left of retractor muscle of right optic tentacle; epiphallus well developed (approx. 50-75 % of penis length); epiphallus and lower vas deferens not joined to penis by connective tissue web; vagina long; oviduct caecum absent or little more than a small lateral pouch. Distal part of suprapedal gland sinuous but not convoluted, lacking a swollen terminal vesicle.
Radula (Figs 58, 64, 67, 71): Length up to 22.5 mm, with up to 85 V-shaped transverse rows of teeth, 3.2-4.5 rows per/mm in adult; formula varies considerably with species (Table 2); rachidian present, but small; inner lateral teeth slender and acuminate, increasing slightly in size; outer 2 or 3 laterals considerably larger, each with a stout quadrate base-plate and curved, sharply pointed cusp; marginal teeth either rapidly or gradually decreasing in size and becoming vestigial at radula margin, but always with 1 or 2 of intermediate size adjacent to outermost lateral tooth, more in A. knysnaensis.
The boundary between the lateral and marginal series is easy to determine in Afrorhytida knysnaensis where the largest tooth (the outermost lateral) has a stout, quadrate base-plate and is followed by a much smaller (0.5-0.66x length of largest tooth) and far less robust tooth with a reduced base-plate (the innermost marginal). In the remaining species, however, the distinction is less clear and the largest tooth is followed by one which is only slightly smaller (0.75-0.9x length of largest tooth) and which retains a robust cusp and well-developed, quadrate base-plate. In this case, though it is not the largest tooth, we have included this latter tooth in the lateral series. For these species therefore, it is the penultimate lateral tooth that is the largest.
In A. trimeni and A. burseyae sp. n. the number of marginal teeth is usually less than 10 and there are more laterals than marginals. In A. knysnaensis and A. kraussi there are more than 10 marginals and they equal or outnumber the laterals.
External anatomy (Figs 6A, 55): Left body lobe of mantle divided into two relatively small lobes separated by a low ridge (Fig. 6A); skin texture moderately granular; neck region usually with a paler longitudinal line extending backward from the base of each optic tentacle, often bordered laterally by a darker line; labial palps present but relatively small; optic and inferior tentacles with a ventrally distended apical bulb; tail region of foot short; genital pore ventral and just posterior to right optic tentacle.
[FIGURE 53 OMITTED]
Distal genitalia (Figs 9B, 53, 54): Penis long, elongate-cylindrical, usually tapering slightly toward its base, often somewhat sinuous in situ, but not strongly so; penis length and thickness of its wall variable and dependent on relaxation state during preservation; internal lumen lined by papillate epithelium (Fig. 54A), papillae coarser than those of Natalina and less tightly packed, somewhat angular and irregularly positioned, but alignment generally longitudinal rather than transverse, particularly in basal region. Apex of penis evidently lacking a distinct papilla, its lumen communicating directly with epiphallus lumen; epiphallus joins penis at U-shaped bend, to which penial retractor muscle is attached. Epiphallus well developed, 0.50-0.75 of penis length, tapering toward its junction with vas deferens, reflexed to lie beside penis, but not joined to it by connective tissue web. Internal morphology of epiphallus exhibiting considerable inter-specific variation (Figs 54B-E), mirroring morphology of spermatophore. In all species its inner wall (facing penis) bears two well-developed longitudinal folds which extend for the full length of the organ, between which is a narrow groove; remaining wall of lumen bears a series of longitudinal ridges of varying strength and length, with microscopic pits in their intervals, in a pattern which appears to vary with species. Pits generally occur where epiphallus wall is thickest and represent the openings of minute diverticulae in which the spermatophore spines are moulded; their arrangement thus determines the pattern of spines on spermatophore; diverticulae usually visible externally as diffuse white specks in epiphallus wall. Vas deferens runs alongside penis base, vagina and free oviduct, sometimes sinuous in the latter region, before it fuses with spermoviduct. It is closely applied to the vagina and oviduct and held in place by connective tissue, but its lower region is free of the penis base.
[FIGURE 54 OMITTED]
Vagina of moderate length (relatively shorter than in Capitina and Natalina) generally of more or less even width, but basally swollen in Afrorhytida kraussi, attached laterally to body wall by a series of well-developed muscle fibres; vagina merges with free oviduct at point of origin of bursa copulatrix duct or just above this; an oviduct caecum is lacking or present merely as a short pouch-like vestibule into which the free oviduct opens, just above the origin of the bursa copulatrix duct (in Afrorhytida knysnaensis and Afrorhytida trimeni); inner wall of vagina with longitudinal folds in 2-3 orders of magnitude; similar but somewhat thicker folds lining free oviduct. Bursa copulatrix duct long and slender, attached to free oviduct by connective tissue and then running beside convoluted spermoviduct (not within its convolutions) to bursa itself, situated posterior to pericardium and kidney; bursa elongate-ovate to pyriform, very thin-walled. Spermoviduct with distinct oviducal and prostatic portions, the former with superficial folds.
Spermatophores (Figs 10, 62, 68): Allospermatophores have been found in the female tract of Afrorhytida burseyae sp. n. and A. kraussi and are discussed in detail under the respective species treatments. These differ considerably in shape, size and ornamentation, suggesting that spermatophore morphology is species specific and may ultimately provide useful supplementary morphological characters to test the validity of the species as currently delimited. However, at present very few spermatophores have been encountered and those of A. knysnaensis and A. trimeni are unknown. The spermatophores of Capitina and Natalina are of a very different form and are compared in the introductory section.
Notes: Afrorhytida has traditionally been considered a subgenus of Natalina (Connolly 1939). However, the morphology of the radula, distal reproductive tract and spermatophores show that Afrorhytida exhibits several character states quite distinct from those present in the Natalina radiation. In addition, molecular data indicate that Afrorhytida represents highly divergent monophyletic lineage worthy of recognition as a separate genus (Moussalli et al. 2009).
Characteristic features of the reproductive tract that separate Afrorhytida from Natalina are the fact that the penis lies to the left of the retractor muscle of the right optic tentacle (to its right in Natalina), the epiphallus and lower vas deferens in Afrorhytida are not connected to the penis by a web of connective tissue, and a distinct oviduct caecum is absent, at most there is a small swelling just above the origin of the bursa copulatrix duct. In terms of the radula, whereas the transition between the lateral and marginal series is abrupt in Natalina, there being no teeth of intermediate size, in Afrorhytida there is always at least one tooth of intermediate size outside the largest lateral.
Afrorhytida comprises a group of medium-sized rhytidids endemic to the Cape region. They occur in a wide range of habitats from coastal fynbos and scrub, to montane fynbos, various types of thicket, Afrotemperate forest and even Nama Karoo. Shell proportions appear to vary considerably within species and to overlap between species, such that species identification based on shell characters alone is frustratingly difficult. We have been able to define species boundaries only through the use of a combination of shell and radula characters, and molecular data. The above notwithstanding, we are confident in our correlation of the species thus identified with the nominal taxa described to date, even though the latter were based on shell characters alone.
Watson (1934) proposed the taxon Hyperrhytida as a section within Afrorhytida, defined largely by radula characters (inner laterals with laterally flanged cusps), and included in it A. trimeni and A. arguta. As shown below these two names in fact refer to a single species and therefore the characters which Watson used to define Hyperrhytida are species-level characters. Although the low number of marginal teeth (<10) in both A. trimeni and A. burseyae sp. n. may represent a synapomorphy providing some support for the existence of an Afrorhytida lineage distinct from Afrorhytida s. s., molecular data do not support a sister group relationship between these two taxa.
Key to species of Afrorhytida 1 Radula with lateral teeth outnumbering marginals. South-eastern and eastern E. Cape 2 -- Radula with marginal and lateral teeth of more or less equal number, or marginal teeth outnumbering laterals. W. Cape and western and central E. Cape 3 2 Shell sculptured with axial ribs which remain strong on last whorl; H:D of adult <0.7; shell colour predominantly brown in fresh specimens. Primarily in forest A. trimeni -- Axial ribs conspicuous on spire whorls, but noticeably weaker or obsolete on last whorl; H:D of adult >0.7; colour distinctly yellowish or greenish brown. Thicket and more open habitats A. burseyae sp. n. 3 Shell lenticular to subglobose, yellowish brown to greenish brown, interior without pinkish lilac sheen; marginal teeth of radula relatively gradually decreasing in size, only the outermost ones vestigial. Catchments of the Sundays and Great Fish rivers and neighbouring coastal areas A. knysnaensis -- Shell lenticular, generally brownish when fresh, interior of fresh shells with a pale pinkish lilac sheen; marginal teeth of radula rapidly decreasing in size, with only 1 or 2 teeth of intermediate size. W. Cape and south-western E. Cape A. kraussi
[FIGURE 55 OMITTED]
Afrorhytida knysnaensis (Pfeiffer, 1846)
Figs 6A, 7B, 9B, 11B, 53, 54A, B, 55A-C, 56-60
Helix knysnaensis: Pfeiffer 1846a (dated 1845): 131; 1846b: 439; 1848: 84; 1853 in 1853-60: 343, No 858, pl. 133, figs 5, 6; Philippi 1847: (37) 85, pl. 7, fig. 5; Krauss 1848: 76; Reeve 1852 in 1851-54: sp. 403. Type loc.: 'Knysna, Cape of Good Hope' [Cuming coll'n]--erroneous and here emended to Fort Beaufort, E. Cape, South Africa.
Helix (Pella) knysnaensis: Pfeiffer 1879 in 1878-81: 102; Tryon 1887: 106, pl. 20, fig. 75.
Aerope knysnaensis: Pilsbry 1889: 277, pl. 9, figs A-G, J.
Natalina knysnaensis: Pilsbry 1893 in 1892-93: 135; 1908 in 1907-08: xi, pl. 52, fig. 4 (lung) [not 1 as stated]; Melvill & Ponsonby 1898: 170; Sturany 1898: 31; Connolly 1912: 94; 1939: 111 [not text-fig. 9 = Afrorhytida kraussi].
Natalina coerneyensis Melvill & Ponsonby, 1894: 91, pl. 1, fig. 2; 1898: 170; Moss 1894: 25, pl. 2, fig. 2; Sturany 1898: 31; Connolly 1912: 92; 1939: 112. Type loc.: Coerney, north of Port Elizabeth, E. Cape. Syn. n.
Rhytida (Afrorhytida) knysnaensis: Mollendorff 1903: 61, pl. 11, figs 1, 2.
Rhytida (Afrorhytida) coerneyensis: Mollendorff 1903: 64, pl. 11, fig. 8.
Natalina insignis Melvill & Ponsonby, 1907: 98, pl. 6, fig. 9; Connolly 1912: 94; 1939: 113. Type loc.: Teafontein farm, between Riebeek East and Grahamstown, E. Cape [Dr Schonland, per Farquhar]. Syn. n.
Natalina (Afrorhytida) knysnaensis: Schileyko 2000: fig. 970.
Etymology: Named after the purported, but evidently erroneous, type locality, Knysna, W. Cape, South Africa.
Identification: A variable species in terms of shell proportions and body coloration. Elevated, subglobose specimens closely resemble Afrorhytida burseyae sp. n., but attain a slightly larger size and have a somewhat wider umbilicus. Depressed specimens may closely resemble A. kraussi kraussi and A. trimeni, but in both of these the shell is of a richer brown hue when fresh and lacks a yellowish or greenish tint. A. kraussi kraussi also has a pinkish lilac blush inside the aperture of fresh shells and A. trimeni has axial sculpture which remains strong on the last adult whorl. The most distinctive features of A. knysnaensis concern its radula which differs from that of all other Afrorhytida species in that the outermost lateral tooth rather than the penultimate one is the largest. Furthermore, it generally has fewer lateral teeth (<10 per half row) and more numerous marginal teeth (>16 per half row), such that the lateral:marginal ratio is 0.50 or less (compared to 1.0 or more in the other species). The outward reduction in size of the marginal teeth is also noticeably more gradual. Juvenile specimens of Natalina cafra cafra may co-occur with A. knysnaensis and be of similar size, but these have a much larger protoconch, less deeply penetrating umbilicus and fewer whorls for their size.
Description (Figs 56, 57): Shell proportions very variable, ranging from subglobose (H:D=0.75-0.86, Figs 57A-E) to lenticular (H:D=0.55-0.65, Figs 57J-L); adult shell comprising 4-5 whorls, the last usually descending somewhat prior to aperture, sometimes conspicuously so; base glossy, apical surface less so, but still retaining some lustre when fresh. Protoconch 3.7-5.2 mm in diameter, apical portion more or less smooth, axial riblets developing only toward end of final whorl and protoconch relatively weakly sculptured compared to other species; protoconch/teleoconch junction usually poorly defined. Apical surface of teleoconch sculptured by close-set axial riblets, these becoming weaker and less well defined toward end of last adult whorl and on base; base also with traces of spiral liration; aperture subcircular to roundly-ovate and somewhat obliquely descending; outer lip slightly thickened and occasionally weakly reflected in adult specimens, sometimes weakly thickened internally in senescent individuals; upper part of outer lip frequently somewhat flattened in depressed specimens; umbilicus of moderate but variable width, wider in depressed specimens than in subglobose ones in which it is partially obscured by reflected upper portion of columella lip.
[FIGURE 56 OMITTED]
Periostracum of fresh specimens usually a shade of yellowish brown with a slight greenish tinge; for the most part relatively uniform, but sometimes with faint axial variation in intensity. Underlying shell and interior of aperture milky-white (no trace of pinkish or lilac hue, cf. Afrorythida kraussi); apical periostracum frequently eroded, even in living specimens.
Dimensions: Largest specimen (BMNH 1563, Grahamstown), diameter 31.0 mm, height 21.1 mm, but few specimens exceeding diameter 25 mm and height 19 mm. H:D of adults 0.55-0.86 (N=42).
Living animal (Figs 55A-C): Coloration very variable, ranging from more or less uniformly pale apricot-orange to dark maroon-black; other specimens more contrastingly coloured with sides of foot pale flesh and dorsal neck region darker grey-black with a paler, dorsolateral, longitudinal stripe on each side extending backward from optic tentacle; tentacles usually darker grey, particularly the optic ones; pedal margin occasionally, but rather rarely, more brightly coloured; tip of tail also often somewhat more intensely pigmented; mantle edge coloration similar to body colour; pigmentation of lung wall variable, usually limited and seldom heavy.
[FIGURE 57 OMITTED]
Radula (Fig. 58): Formula 1+(7-10) (1) +(17-24) (N=8); length up to 19 mm, with 60-80 V-shaped rows of teeth, 3.6-4.4 rows/mm in adult; lateral and marginal series clearly differentiated. Rachidian short, its cusp and base-plate more or less equal in length; inner lateral teeth more or less parallel-sided, tapering to a point at tip, increasing slightly in size from first to fifth or sixth; outer 2 or 3 laterals considerably larger, with a strong quadrate base-plate and well-developed curved cusp (length of cusp variable between individuals, frequently relatively stout); outer lateral tooth the largest. Marginal teeth slender and more delicate with a much reduced base-plate, innermost one 0.50-0.66 length of outer lateral, remainder decreasing gradually in size, in decreasing increments, toward radula margin, only those at the extreme edge truly vestigial.
[FIGURE 58 OMITTED]
Distal genitalia (Figs 9B, 53, 54A, B): See generic description. Epiphallus 75 % or more of penis length, but variable in proportions and curvature, sometimes with distinct greyish pigmentation; distal half broader, progressively narrowing toward vas deferens; mid region of lumen with a transverse ring of four to five short, swollen, longitudinally orientated, white, digit-like pilasters, each narrowly attached to lumen wall; smooth, low ridges extend from these toward vas deferens, often greyish in colour; lumen wall anterior to pilasters with indistinct ridges between each of which lies a longitudinal row of punctations marking the openings of minute diverticulae in lumen wall, these extending to penial end of epiphallus and visible as striae in cut wall. Papillae lining penis lumen loosely arranged in longitudinal rows.
No spermatophores have been found, but the morphology of the epiphallus suggests that the tail region of the spermatophore may bear weak, longitudinal ridges and the anterior half will possess four to five rows of spinose projections.
Type material (Fig. 56): Lectotype of Helix knysnaensis Pfeiffer, 1846 in BMNH (20080612) (designated Connolly 1912: 94), diameter 24.2 mm (Figs 56A-C), plus two paralectotypes (20080613). Holotype of Natalina coerneyensis Melvill & Ponsonby, 1894 in BMNH (19184.108.40.206), diameter 22.5 mm (23.3 mm fide Connolly 1939) (Figs 56D-F). Holotype of Natalina insignis Melvill & Ponsonby, 1907 in BMNH (1902.6.26.12) [Dr Schonland], diameter 29.4 mm (Figs 56G, H).
Additional material examined (all NMSA unless otherwise indicated): SOUTH AFRICA: North-western E. Cape (west of Great Fish R.): Nieu Bethesda area, Kompasberg slopes (31.79092[degrees]S:24.55475[degrees]E), 1600 m, water course krantz in rocky grassland, beneath bushes and grass clumps, Herbert, Davis & Cole, 15/iii/2008, (W6097); Cradock (32.16220[degrees]S:25.60580[degrees]E), 921 m, succulent karoo, at the base of Acacia, M. Cunningham, viii/2003 (W4248); Cradock (32.183[degrees]S:25.617[degrees]E) (B0028, V5276, V6635, BMNH 19220.127.116.116-7); Cradock (32.183[degrees]S:25.617[degrees]E), ix/1897 (E7914); Cradock (32.183[degrees]S: 25.617[degrees]E), amongst loose boulders (1496); Graaff-Reinet (32.25[degrees]S:24.55[degrees]E) (W1374); Graaff- Reinet, Camdeboo Nat. Park, Valley of Desolation view site (32.26585[degrees]S:24.49203[degrees]E), 1350 m, in deep shaded gully between dolerite cliffs, D. Herbert, L. Davis & M. Cole, 14/iii/2008 (W6093); Mountain Zebra Nat. Park (32.24683[degrees]S:25.43352[degrees]E), 1450 m, rocky outcrop on hilltop ridge, amongst rocks and under small bushes, Herbert, Davis & Cole, 17/iii/2008 (W6118); Witmoss, N of Cookhouse (32.533[degrees]S:25.733[degrees]E), A. Reeve, ex J. Farquhar (B0046, BMNH 1918.104.22.1688-9); Somerset East, Glen Avon Nat. Res. (32.67436[degrees]S: 25.64463[degrees]E), 978 m, valley thicket/indigenous forest, A. Moussalli & D. Stuart-Fox, 24/xii/2005 (W4847); ditto, 'Craigie Burn' (32.6850[degrees]S:25.6783[degrees]E) (B0025); ditto, Bosberg (32.70[degrees]S:25.55[degrees]E) (3054, B0030, V6845); ditto, slopes of Bosberg (32.70257[degrees]S:25.57605[degrees]E), indigenous woodland, in leaf-litter, D. Herbert, M. Bursey & G. Redman, 22/i/2002 (V9790); ditto, Bosberg Nat. Res. (32.70734[degrees]S:25.55959[degrees]E), 777 m, indigenous forest, under rocks, A. Moussalli & D. Stuart-Fox, 24/xii/2005 (W4643); ditto, vicinity of camping grounds (32.70734[degrees]S:25.55959[degrees]E), 771 m, indigenous forest, in leaf-litter, A. Moussalli & D. Stuart-Fox, 16/iii/2005 (W4846); Somerset East (32.717[degrees]S:25.583[degrees]E), ex Mrs Howard and Dr Becker (B0027, B0026, V6841); Jansenville, Meerlust Suid farm (32.87148[degrees]S:24.64085[degrees]E), rocky area with dense aloes and bush clumps, under dead aloes, D. Herbert, L. Davis & M. Cole, 12/iii/2008 (W6068); ditto (32.86520[degrees]S:24.67360], 450 m, rocky N facing hillside with aloes, noors and bush clumps, under dead aloes, D. Herbert, L. Davis & M. Cole, 11/iii/2008 (W6053); ditto, Fontein Camp (32.85977[degrees]S: 24.63966[degrees]E), 450 m, rocky area with aloes, noors and bush clumps, under dead aloes, D. Herbert, L. Davis & M. Cole, 11/iii/2008 (W6060); Jansenville, Alwynsfontein farm (32.87949[degrees]S:24.60543[degrees]E), 500 m, valley floor with aloes, noors and bush clumps, under dead aloes, D. Herbert, L. Davis & M. Cole, 11/ iii/2008 (W6067); Koedoeskop farm SE of Somerset East (32.9753[degrees]S:25.1717[degrees]E), 498 m, on stony ridge, specimen found trying to reach dead mouse in mammal trap, O. Bourquin, 06/xi/1998 (V6774). Southern E. Cape (south of Great Fish R.): Port Elizabeth (33.917[degrees]S:25.600[degrees]E), F. Cruden, ii/1922 (1498, E7903); ditto, A.J. Peile (NMH 2242); ditto, MacAndrew coll'n, 05/i/1909 (BMNH un-numbered); Addo area, 6 km SW (33.593664[degrees]S:25.648581[degrees]E), 30 m, aloes and other succulents, leg. B. Muller & M. Mostovski, 12/vii/2009 (W6930); Coerney (holotype of Natalina coerneyensis) (33.4500[degrees]S:25.7333[degrees]E) (BMNH 1922.214.171.124); Grahamstown, Teafontein farm (holotype of Natalina insignis) (33.23300[degrees]S:26.25417[degrees]E), Dr Schonland via J. Farquhar (BMNH 1902.6.26.12); Grahamstown, 'St J. M.', 31/iii/1909 (BMNH MacAndrew coll'n 1563); Port Alfred (33.6[degrees]S:26.9[degrees]E) (W1395). Central E. Cape (north-east of Great Fish R.): Baviaans Valley between Bedford and Tarkastad, Wapadskloof, Huntley Glen farm (32.40945[degrees]S: 26.11472[degrees]E), under fallen stems ofAloe ferox and under stones, M. Bursey, 31/xii/2006 (W5255); Bedford (32.683[degrees]S:26.083[degrees]E), J. Farquhar (B0015); Alice (32.783[degrees]S:26.833[degrees]E) (V6839); Alice area, Breakfast Vlei (33.0833[degrees]S:26.9500[degrees]E) (BMNH un-numbered); Fort Beaufort (32.783[degrees]S:26.633[degrees]E), J.S. Taylor, x/ 1945 (V7729); Fort Beaufort, agricultural college farm (32.80544[degrees]S:26.63381[degrees]E), valley thicket with aloes and euphorbs, in leaf-litter under fallen aloes, D. Herbert, L. Davis & M. Bursey, 07/iii/2007 (W5211); ~13 km N of Double Drift Game Res. (32.86658[degrees]S:26.81436[degrees]E), 573 m, valley thicket, under dead aloes, A. Moussalli & D. Stuart-Fox, 2/xii/2005 (W4749, W5164).
Additional literature records (Connolly 1939; material not seen): SOUTH AFRICA: E. Cape: Enon, north of Port Elizabeth (33.40[degrees]S:25.55[degrees]E), Hartwig; Sandflats Station [nr Paterson] (33.43[degrees]S:26.95[degrees]E), J. Crawford.
Distribution (Fig. 59): Endemic to E. Cape; occurs in the catchments of the Sundays and Great Fish rivers, from low altitudes near the coast to 1600 m in the Sneeuberge. The original type locality (Knysna) is evidently erroneous (see notes below for emendation).
Habitat: Found largely in the Albany Thicket biome (Mucina & Rutherford 2006), and in isolated mist-belt forest patches within this, but also extending into the south-eastern Nama Karoo. Evidently catholic in its habitat requirements, but favouring patches of relatively dense vegetation. These, however, vary greatly in plant composition from forest to mixed woody thicket, spekboom thicket (Portulacaria afra Jacq.), Aloe--Euphorbia dominated scrub and, at higher altitudes, shrubby rock outcrops in more open Karoo escarpment grassland. Lives buried in leaf-litter beneath shrubs and bush clumps, under logs and fallen aloes, and amongst rocks; evidently not rare, but population densities generally low.
Notes: The material here treated as Afrorhytida knysnaensis exhibits considerable variation in shell proportions (Fig. 57). This notwithstanding, the sculpture and coloration of the teleoconch is relatively consistent, as is the weak axial sculpture on the protoconch and the morphology of the radula, in which the outermost lateral tooth is the largest and there are many marginal teeth of intermediate size. The material thus identified forms a well-supported monophyletic clade in analyses of molecular data (Moussalli et al. 2009), corroborating the morphological evidence. There is, however, considerable genetic diversity within this clade (Fig. 1), indeed the highest level exhibited of the all the species examined here (e.g., mean uncorrected P-distances of 0.49 for the protein coding mitochondrial gene COI). Thus, there exists the possibility that this taxon constitutes more than one cryptic species.
[FIGURE 59 OMITTED]
H: D measurements indicate a north-west to south-east trend in shell proportions, with shells from the north-west being consistently less globose than those from the south-east (Fig. 60). The dotted line in this figure, separating subglobose and lenticular populations, when redrawn on the distribution map to separate the same individuals (Fig. 59), runs approximately south-west to north-east (St Francis Bay to Molteno), dividing the relatively elevated, subglobose south-eastern specimens from the more depressed, lenticular northwestern individuals. Additionally, within the south-eastern region, shells from the Port Elizabeth area are noticeably smaller (adult diameter approx. 20 mm). There is, however, no clear disjunction evident within this north-west vs south-east trend in shell proportions (Fig. 60). The line has been positioned for illustrative purposes, and in reality the variation is evidently more clinal than categorical. Some specimens are thus of intermediate proportions, but this notwithstanding, the trend is clear.
Somewhat similar geographic structuring is evident in DNA sequence data (Moussalli et al. 2009), with analyses of such data identifying strongly supported clades from the Somerset East-Cradock area and from the eastern part of the Fish River valley (Fort Beaufort and Greater Fish River Conservancy). However, individuals from other localities do not cluster in a N-W to S-E pattern consistent with this. At present sequence data are available for too few specimens to determine the degree of concordance between phylogeographic structure and the geographic variation evident in shell proportions. Alternatively variation in shell proportions may not be genetically correlated, but may instead be determined by N-W to S-E variation in environmental parameters such as temperature and/or rainfall.
[FIGURE 60 OMITTED]
The small, subglobose individuals from the Port Elizabeth area are currently known from shells alone, there is thus no anatomical or molecular data to confirm that we are correct in referring them to A. knysnaensis. In addition to being small and relatively globose, they have a more elevated spire and a more acute apex (Fig. 57B). In this respect it is noteworthy that Pilsbry (1889) illustrated a radula under the name Aerope knysnaensis (locality unspecified) with 12 lateral teeth per half row. This figure is higher than any of the material examined herein, but an old radula slide in the Natal Museum labelled "Natalina knysnaensis, Port Elizabeth' (not associated with a shell) likewise has 12 lateral teeth per half row. Since Pilsbry's material (sent by J. Ponsonby) may well have originated in the Port Elizabeth area, there is a possibility that this conchologically divergent population may in addition possess a somewhat distinct radula and perhaps represent a separate and undescribed species. Attempts to collect additional material in the Port Elizabeth area, so that this possibility could be explored further, have been unsuccessful.
The locality given in the original description is evidently erroneous, as is commonly the case with material from the Hugh Cuming collection (Dance 1986). Knysna lies some 200 km west of the westernmost known records for this species. In accordance with recommendation 76A.2 of the Code (ICZN 1999), we here emend the type locality to be Fort Beaufort. Specimens closely resembling the type series have been found recently in the vicinity of this town. The fort was constructed as a military frontier defence in 1822 and became established as a town in 1837. It is thus possible that material from this locality could have come into the possession of early 19th century British collectors such as Cuming, well before its description in 1846.
Synonymy: Connolly (1939) maintained 'Natalina" knysnaensis and 'N.' coerneyensis as distinct species, but stated that he would have placed coerneyensis 'without hesitation in the synonymy of knysnaensis^, were it not for differences in the radula. His assessment of the radula of 'N.' knysnaensis was based on a radula slide identified under that name in the Gwatkin collection (present in BMNH) with the locality "Cape". This he compared with another radula slide in the same collection identified as 'N.' coerneyensis and the figure of the radula of 'N.' coerneyensis (from Coerney) published by Moss (1894). Re-evaluation of Connolly's illustration of the 'N.' knysnaensis radula (Connolly 1939, text-fig. 9) and the slide still present in the BMNH, in the light of the data now available, indicates it was from an incorrectly identified specimen. The outer lateral teeth are relatively slender and the largest is clearly the penultimate one rather than the outermost one. This combined with the relatively large number of marginal teeth (16 per half row) indicates that the radula was in all probability from a specimen of A. kraussi. Since subglobose specimens typical of A. knysnaensis have a radula indistinguishable from that of topotypic specimens of 'N.' coerneyensis, we conclude that Natalina coerneyensis Melvill & Ponsonby, 1894 is a junior synonym of A. knysnaensis. Although the type material of A. knysnaensis is incorrectly localised, it is clearly subglobose and H:D ratios indicate that both names are likely to apply to the south-eastern population discussed above.
Natalina insignis Melvill & Ponsonby, 1907 is anatomically unknown. Attempts to find living material at the type locality were unsuccessful. Although large, the holotype falls within the range of variability exhibited by A. knysnaensis and a specimen of very similar shape (NMSA V6774 from Koedoeskop farm, SE of Somerset East (Fig. 57F), ca 120 km west of the type locality of N. insignis) has a radula typical of A. knysnaensis and groups within this clade in molecular analyses (Moussalli et al. 2009). We therefore consider this name to be a further synonym of A. knysnaensis. In terms of the H:D ratio these specimens are of somewhat intermediate shell proportions.
Afrorhytida kraussi (Pfeiffer, 1846)
Moussalli et al. (2009) have shown that Afrorhytida material occurring in the mountains of the southern Cape Fold Belt (Langeberge to Port Elizabeth) and adjacent coastal regions constitutes a monophyletic lineage which was identified as the A. kraussi complex. From a morphological perspective this complex includes two clearly distinct forms. Firstly, a form with an essentially brown shell, representing typical A. kraussi, which is widespread and occurs in a variety of habitats from southern Afrotemperate forest to montane sandstone fynbos, and secondly a smaller form with a thicker, paler shell which is evidently confined to coastal habitats in the De Hoop region. Since this latter form is clearly and consistently diagnosable we describe it as a new taxon, choosing for the present to rank it as a subspecies within a broadly interpreted A. kraussi, primarily on account of the molecular data which shows it to cluster within this complex.
As a whole, the A. kraussi complex has high genetic diversity (mean uncorrected Pdistances of 0.44 for the protein coding mitochondrial gene COI; refer to Fig. 1) and exhibits strong west-east phylogeographic structure (Moussalli et al. 2009). This structure is more consistent with the predominantly west-east distribution of the material, than it is with the habitat of origin (i.e. forest vs fynbos). However, other than for the De Hoop material, we have been unable to identify any clear morphological characters which could serve to discriminate between the constituent subclades, and which might thus justify further specific or subspecific division. This notwithstanding, there is some evidence that the genetically divergent lineage occurring in isolated Afrotemperate forest patches at the western limit of the range (i.e. Grootvadersbosch and Tradoupas) exhibits a discernable trend toward larger size and frequently has a distinct reddish head-foot coloration (see below). In contrast, morphologically similar and geographically proximate specimens from sandstone fynbos in the mountains inland of Mossel Bay are widely disjunct genetically, yet there is no obvious physical feature in this area which stands out a potential biogeographic barrier. Given apparently anomalous patterns such as this, and the paraphyly resulting from the nesting of the morphologically distinct De Hoop lineage within the typical A. kraussi clade, it is evident that resolution of taxonomic uncertainties and phylogenetic relationships within the A. kraussi complex must await more detailed study of material more broadly representative the distribution of the species, particularly with respect to DNA sequence data.
Afrorhytida kraussi kraussi (Pfeiffer, 1846)
Figs 10C, 54E, 55D, E, 61-63, 64A-D, 65D
Helix kraussi: Pfeiffer 1846c: 70; 1848: 197; Krauss 1848: 77, pl. 4, fig. 24; Reeve 1854 in 1851-54: sp. 1391. Type loc.: 'Outeniquaprom. bon. spei. (Krauss.)', later given as 'In sylvis Outeniqua, provinc. George' by Krauss (1848).
Helix sturmiana Pfeiffer, 1853a: 253; 1853b: 150; 1854: 142; 1854 in 1853-60: 397, No 944, pl. 144, figs 3, 4; Reeve 1853 in 1851-54: sp. 1132; Pilsbry 1890 in 1890-91: pl. 36, figs 28, 29. Type loc.: originally unknown (Cuming Coll'n), later given as Delagoa Bay [southern Mozambique], but without justification (Pfeiffer 1878 in 1878-81: 62 as Macrocyclis).
Macrocyclis sturmiana: Pfeiffer 1878 in 1878-81: 62.
Helix (Acusta) kraussi: Tryon 1888: 50, pl. 10, fig. 30.
Dorcasia kraussi: Pfeiffer 1879 in 1878-81: 187; Sturany 1898: 50; Pilsbry 1895 in 1893-95: 173.
Phasis sturmiana: Sturany 1898: 41; Pilsbry 1893 in 1893-95: 37.
Helix (Ampelita) sturmiana: Pfeiffer 1879 in 1878-81: 184.
Rhytida kraussi: Melvill & Ponsonby 1898: 170 (= sturmiana).
Rhytida (Afrorhytida) kraussi: Mollendorff 1903: 63, pl. 11, figs 5, 6.
Natalina kraussi: Connolly 1912: 94; 1925: 122; 1939: 112, pl. 3, figs 8-10.
Natalina liliacea Preston, 1912: 17; Connolly 1912: 95; 1939: 114. Type loc.: 'Knysna Forest, Cape Colony' [Cox]. Syn. n.
Natalina knysnaensis: Connolly 1939: text-fig. 9 (radula).
Natalina (Afrorhytida) kraussi: Bruggen 1970: 468.
Not Rhytida kraussi: Moss 1894: 25, pl. 1 fig. 3; nor Rhytida Kraussii [sic]: Cooke 1895: 232 [= Nata vernicosa (Krauss, 1848)].
Etymology: Named for Christian Ferdinand Friedrich Krauss (1812-91), the early German explorer-naturalist and later director of the natural history museum in Stuttgart, who wrote the first scientific work devoted to southern African molluscs (Krauss 1848).
Identification (Fig. 61): The shell of Afrorhytida k. kraussi is considerably less globose than that of A. burseyae sp. n. and typical (south-eastern) specimens of A. knysnaensis. In shell proportions and colour it most closely resembles A. trimeni, but in the present species the last adult whorl is generally less deep and has less distinct axial ribs. Additionally, in A. trimeni the radula has distinctively shaped inner lateral teeth and fewer marginal teeth (see below). The more lenticular shells of north-western specimens of A. knysnaensis are generally of a paler, somewhat yellowish or greenish hue and the radula of that species has more strongly developed inner marginal teeth and the outer lateral tooth rather than the penultimate one is the largest. In fresh specimens of A. k. kraussi the pinkish lilac sheen of the interior is also diagnostic.
Description: Shell generally lenticular, but proportions somewhat variable; adult shell comprising 4.0-4.5 whorls, the last frequently descending somewhat prior to aperture in adult specimens; base glossy, apical surface less so. Protoconch 4.5-5.0 mm in diameter, with distinct, relatively coarse axial riblets more or less throughout. Apical surface of teleoconch sculptured by close-set axial riblets, these becoming weaker and less well defined toward end of last adult whorl and on base; base also with traces of spiral liration; aperture subcircular to roundly ovate and somewhat obliquely descending; outer lip thin but not membranous (in adult), its basal portion and columella lip slightly thickened; upper part of columella lip weakly reflected; umbilicus relatively wide and not obscured to any appreciable degree by reflected columella lip.
Periostracum of fresh adult specimens usually predominantly brown, without a yellowish or greenish tinge, but young specimens sometimes paler and somewhat greenish; all specimens tending to fade and eventually becoming slightly yellowish; coloration generally uniform, but occasionally with slight axial variation in intensity. Underlying shell whitish, interior of aperture with a pale, but distinct pinkish lilac wash.
Dimensions: Largest specimen (NMSA W4748, Marloth Nat. Res.), diameter 28.4 mm, height 18.4 mm, but some specimens appear to be adult at diameter 21 mm; H:D of adults 0.48-0.67 (N=39).
Living animal (Figs 55D, E): Few specimens have been examined or photographed alive, but the coloration of the living animal is evidently variable. Head-foot of specimens from both forest and fynbos habitats in the Knysna-Tsitsikamma area (typical) generally shades of dark brown (Fig. 55D), usually darkest in neck region and tail, but with a conspicuous pale, dorsolateral, longitudinal stripe on each side of neck, extending backward from optic tentacle; sides of foot paler; optic tentacles dark grey-brown; pedal margin may be tinged with orange; mantle edge mostly dirty yellowish cream; lung wall usually heavily marked with black. Specimens from Grootvadersbosch (Fig. 55E), however, though similarly patterned, are primarily of an orange to reddish hue, frequently brightly so along the dorsal neck and pedal margin.
[FIGURE 61 OMITTED]
Radula (Figs 64A-D): Formula 1-15)+(11-16) (N=5); length up to 22.5 mm, with 70-85 V-shaped rows of teeth, 3.2-4.3 rows/mm in adult. Rachidian cusp somewhat longer than its base-plate. Inner lateral teeth more or less parallel-sided, apically acuminate and differing little in size; outermost 3 or 4 lateral teeth considerably larger, with a stout elongate-quadrate base-plate and long, slender, gently curved, sharply pointed cusp; penultimate lateral larger than outermost one; precise shape and curvature of outer laterals somewhat variable between individuals. Innermost marginal tooth relatively large (0.50-0.75 length of outer lateral), the second and subsequent marginals very much smaller and essentially vestigial.
Distal genitalia (Fig. 54E): See generic description. Epiphallus 75 % or more of penis length, broadest near penis, tapering slowly toward vas deferens and merging smoothly therewith; occasionally with distinct greyish pigmentation; inner side of lumen wall (that adjacent to penis) with two strong folds with an intervening groove running entire length of epiphallus; remaining lumen wall with 2 or 3 low longitudinal ridges in thickened portion nearer to penis, with a row of minute punctations (sometimes paired) in their intervals, these extending to penial end of epiphallus; punctations represent openings of slender diverticulae in epiphallus wall which are visible as striae in cut wall; lumen wall nearer to vas deferens smooth or with shallow ridges, but no punctations.
Spermatophore (Figs 10C, 62): A single allospermatophore was found in a specimen from Grootvadersbosch (collected in mid October). It was situated in the upper vagina and free oviduct; the anterior half occupying almost the entire length of the free oviduct and the posterior half extending well down into the upper vagina, the opening of the bursa copulatrix duct more or less level with the middle of the spermatophore. Spermatophore itself S-shaped and twisted, approx. 20 mm in total length (straightened); anterior third slender and spinose; posterior two-thirds smooth, comprising a somewhat broader mid-piece, tapering to an acuminate tail. Anterior region somewhat quadrate in cross section, the angles on the convex surface set with a row of close-set, antler-like projections, each comprising a narrow stalk which divides into a branched array of 5-8 sharp spines; these spinose ridges continue posteriorly to start of mid-piece, diminishing and disappearing soon thereafter; a third row of similar projections present on one side of head region, but this terminating abruptly, some distance prior to the other rows; concave surface of anterior half smooth, with angular margins, broadening on midpiece. No obvious vent present in tail region, but concave wall of mid-piece evidently thin and perhaps representing rupture site for sperm release.
Type material: Holotype of Helix kraussi Pfeiffer, 1846 in Stuttgart Museum, now lost (cf. Herbert & Waren 1999), but illustrated by Connolly (1939: pl. iii, figs 8-10), diameter 20.7 mm [considerably smaller than the measurements given by Pfeiffer (1846c) and Krauss (1848). Holotype ofHelix sturmiana Pfeiffer, 1853 in BMNH (20080064), diameter 20.8 mm (Fig. 61K). Holotype of Natalina liliacea Preston, 1912 in ISNB MT/525059 (Dautzenberg Coll'n), diameter 20 mm, height 12.3 mm (the height of 16.5 mm given by Preston is clearly an error) (Figs 61A-C); paratype in BMNH (19126.96.36.199), diameter 20.2 mm, height 12.65 mm (20.5 mm and 13.8 mm fide Connolly 1939).
Additional material examined (all NMSA unless otherwise indicated): SOUTH AFRICA: Langeberge: Marloth Nat. Res. (33.98975[degrees]S:20.45439[degrees]E), Afrotemperate forest, A. Moussalli & D. Stuart-Fox, 23/ii/ 2005 (W4748); Swellendam area, Langeberge Mts, northern side (33.967[degrees]S:20.483[degrees]E), 1250 m, in collapsed mole-hill, V. Millard, i/2001 (V8788); Tradoupas, approx. 10 km S of Barrydale (33.97660[degrees]S:20.70311[degrees]E), 353 m, riparian indigenous forest/ fynbos, A. Moussalli, 26/viii/2006 (W4678); Grootvadersbosch Nat. Res. (33.99595[degrees]S:20.81288[degrees]E), 402 m, Afrotemperate forest, in leaf-litter, A. Moussalli & D. Stuart- Fox, 22/ii/2005 (W3350); Grootvadersbosch Nat. Res. (33.99595[degrees]S:20.81288[degrees]E), 402 m, Afrotemperate forest, in leaf-litter, A. Moussalli & D. Stuart-Fox, 22/ii/2005 (W3351); Grootvadersbosch (33.983[degrees]S:20.830[degrees]E) (W889); Grootvadersbosch Nat. Res. (33.98197[degrees]S:20.83363[degrees]E), Afrotemperate forest, in leaf-litter under logs, D. Herbert & L. Davis, 13/x/2007 (W5803); Langeberge, Lemoens Hoek Mts (Grootberg] (33.917[degrees]S: 20.867[degrees]E), K.H. Barnard (SAMC A7244). Outeniekwaberge and Swartberge: Herbertsdale area, Cloetesberg, Cloetespas (33.92083[degrees]S:21.76028[degrees]E), 375 m, dry fynbos, under rocks, M. Cunningham, 5/viii/2003 (W3207); Herbertsdale area (34.04594[degrees]S:21.88528[degrees]E), 360 m, K. Tolley, 28/xi/2005 (W4099); Attakwasberge (33.82580[degrees]S:21.9250[degrees]E), 560 m, montane fynbos, under rocks, M. Cunningham, viii/2003 (W4780); Swartberg Pass, between Prince Albert and Oudtshoorn (33.35[degrees]S:22.05[degrees]E), K.H. Barnard (BMNH 1937. 12.30.1380); Engelseberg summit (33.86940[degrees]S:22.13420[degrees]E), 1500 m, montane fynbos, under rocks, M. Cunningham, viii/2003 (W3211); Montague Pass, north of George (33.89142[degrees]S:22.42912[degrees]E), 620 m, montane fynbos, under rocks, A. Moussalli & D Stuart-Fox, 11/iii/2005 (W4849); Prince Albert, Meiringspoortberg (33.4167[degrees]S:22.5500[degrees]E), 1850-2000 m, K.H. Barnard (NMH 19188.8.131.524). Coastal southern Cape (Wilderness-Tsitsikamma-St Francis Bay): Wilderness area (33.983[degrees]S:22.583[degrees]E), indigenous forest, J.S. Taylor, 1964/5 (V5196, V6578, V6579, V6580); Wilderness, Kaaimansrivier (33.983[degrees]S:22.583[degrees]E), J.S. Taylor, 21/xi/1964 (V5198); Wilderness, Touwsrivier (33.983[degrees]S:22.583[degrees]E), J.S. Taylor, 19/ix/1964 (V5197); Wilderness Nat. Park, Touwsrivier (33.98348[degrees]S:22.60949[degrees]E), indigenous forest, deep in leaf-litter, A. Moussalli & D. Stuart-Fox, 13/iii/2005 (W4784); Sedgefield (34.0333[degrees]S:22.7833[degrees]E), C. Vernon, 15/iii/ 1985 (ELM D11079); 4 km west of Keurhoek (33.95191 [degrees]S:22.91220[degrees]E), indigenous forest, A. Moussalli & D. Stuart-Fox, 12/iii/2005 (W4747); Knysna Forest (holotype Natalina liliacea) (34.033[degrees]S:23.033[degrees]E) (ISNB/ MT/525059); ditto, MacAndrew coll'n, ex Preston, 19/vi/1911 (BMNH 1563); Knysna, Featherbed Nat. Res. (34.08040[degrees]S:23.06361[degrees]E), indigenous forest, in leaf-litter, A. Moussalli, 22/viii/2006 (W4671); Knysna, Diepwalle region, vicinity of King Edward VIII tree (33.95656[degrees]S:23.15256[degrees]E), 423 m, indigenous forest, in deep leaf-litter, A. Moussalli & D. Stuart-Fox, 12/iii/2005 (W4845); Knysna area, Harkerville Nat. Res., Kranshoek Trail (34.08713[degrees]S:23.22577[degrees]E), 29 m, Afrotemperate forest, under rock, A. Moussalli, 21/viii/ 2006 (W4667); Nature's Valley, Salt River area (33.983[degrees]S:23.533[degrees]E), indigenous forest, D. Herbert, 19/ix/ 2003 (W1178); Tsitsikamma Mountain, Formosa Peak Trail (33.86390[degrees]S: 23.70190[degrees]E), fynbos, under rocks, M. Cunningham, 05/iii/2003 (W3212); Baviaanskloof wilderness area, Kougaberge (33.67492[degrees]S: 24.20997[degrees]E), fynbos, under stones, D. Herbert, 10/x/2000 (V8621); Van Staden's River (ca 33.75[degrees]S:25.20[degrees]E), 1891 (V7799); Lady's Slipper Nat. Res., Van Stadensberg, (33.89091[degrees]S:25.26659[degrees]E), montane fynbos, amongst rocky outcrop after fire, A. Moussalli & D. Stuart-Fox, xii/2005 (W6176); ditto (33.88941[degrees]S: 25.27019[degrees]E), 560 m, Kouga grassy sandstone fynbos with abundant Watsonia, in pockets of fine dark soil on rock outcrops, D. Herbert, L. Davis & M. Cole, 08-057, 22/ix/2008 (W6426).
[FIGURE 62 OMITTED]
Additional literature records (material not seen): Langeberge, Zuurbrak Peak (33.85[degrees]S:20.65[degrees]E), 1400 m (Connolly 1939); Swartberg Pass, Platberg (33.317[degrees]S:22.030[degrees]E), ca 1550 m, under stones, 5-6/i/1951 (Bruggen 1970); Outeniqua, George District, Krauss (Connolly 1939); Outeniqua Mts, Robinson Pass (33.8830[degrees]S:22.0167[degrees]E), 615 m, under stones, 7/i/1951 (Bruggen 1970); Montagu Pass, Doorn River (33.883[degrees]S:22.430[degrees]E), Haughton (Connolly 1939); Knysna (34.033[degrees]S:23.033[degrees]E), Power (Connolly 1939); Plettenberg Bay, Keurbooms River bush (34.017[degrees]S:23.417[degrees]E), Barnard (Connolly 1939, as N. liliacea); Kromme River (? Kromrivier, Kareedouberge, 33.99[degrees]S:24.30[degrees]E), Moran (Connolly 1939).
Rejected literature records: Grahamstown (33.300[degrees]S:26.533[degrees]E), Miss Glanville, fide Layard (Connolly 1939); Great Fish Point area, Tharfield farm (33.5500[degrees]S:27.0167[degrees]E), Miss Bowker (Connolly 1939).
Distribution (Fig. 63): Endemic to the south-central regions of the Cape, from the western Langeberge in the west, eastwards to Van Stadensberg in the St Francis Bay area, from the coastal hinterland through the Outeniekwaberge and reaching the Groot Swartberge inland of the Little Karoo; from low altitudes near the coast to 2000 m in the Groot Swartberge. Literature records from further east (Grahamstown and Great Fish Point) are almost certainly incorrect, despite being recorded by Connolly (1939). More probably they refer to specimens of Afrorhytida knysnaensis or A. trimeni. For most of its range, A. kraussi is the only Afrorhytida present, but there is possible sympatry with both A. knysnaensis and A. trimeni in the greater Port Elizabeth area.
[FIGURE 63 OMITTED]
Habitat: Evidently occurs at low density in a wide variety of habitats from southern Afrotemperate forest to sandstone fynbos at higher altitudes in the mountains of the Cape Fold Belt; in leaf-litter and under logs in forest habitats, and under rocks, amongst clumps of vegetation and in pockets of soil on rock outcrops in fynbos habitats.
Notes: Shells vary considerably in shape, size and umbilical width. Those from fynbos habitats at higher altitudes tend to be smaller, whilst those from isolated forests in the west (e.g., Grootvadersbosch) tend to be largest. The latter also have conspicuously more red pigmentation on the head-foot and furthermore appear to constitute a genetically distinct lineage (Moussalli et al. 2009). Similarly, Tolley and Burger (2007) have also shown that the Grootvadersbosch population of the dwarf chameleon Bradypodion damaranum (Boulenger, 1887) is genetically distinct from the remaining population in the Outeniekwa-Tsitsikamma region. The Grootvadersbosch forest is also home to two narrowly endemic subulinid land snails, Euonyma barnardi Connolly, 1929 and E. decipiens Connolly, 1929.
Synonymy: Melvill and Ponsonby (1898) and Connolly (1912, 1939) treated Helix sturmiana Pfeiffer, 1853 as a synonym of the present species. The holotype originated from the Cuming collection and was of unknown provenance, but Pfeiffer later cited Delagoa Bay (environs of Maputo, Mozambique), though without explanation (Pfeiffer 1878 in 1878-81). Since no Afrorhytida species are known from north of E. Cape, this is without doubt erroneous. The holotype is almost identical in shape to specimens of A. kraussi from the Wilderness area (compare Figs 61J and 61K) and it is quite possible that early collectors could have obtained material from this region. We concur with prior authors in treating Helix sturmiana Pfeiffer, 1853 as a synonym of A. kraussi.
Connolly (1939) correctly noted that Natalina liliacea Preston, 1912 was less globose than [typical] specimens of Afrorhytida knysnaensis, but it is puzzling that he did not compare it with A. kraussi, particularly given that the localities he cited for N. liliacea overlap extensively with those he gave for A. kraussi. We consider that the pinkish lilac blush typically seen in the aperture of N. liliacea (and from which the name derives) is a character likewise present in fresh specimens of A. kraussi kraussi. Although Pfeiffer (1846c) did not mention this in his original description of Helix kraussi, when discussing the species Krauss himself stated 'Die Mundung selbst ist be dem kleinen und wohlerhalten Exemplar blass violett' ['The aperture itself of the small and well preserved specimen is pale violet'] (Krauss 1848: 77). Connolly indicated that the shell of N. liliacea was 'prone to assume a distinct lilac hue in rather weather-worn condition' indicating that he misinterpreted the origin of the species name which relates to a feature of fresh rather than weather-worn shells. Since we can find no characters by which these two nominal taxa can be distinguished, we place Natalina liliacea Preston, 1912 in synonymy with Afrorhytida kraussi kraussi. The type localities (Knysna and the George district respectively) are not far distant (<60 km apart), and a forested habitat is specifically mentioned for both.
Conservation: Afrorhytida kraussi kraussi occurs over an extensive area of the southern Cape (E-=W distance approx. 450 km) and is known to occur in a number of formally protected areas. These include both low altitude forest habitats as well as montane sandstone fynbos. This notwithstanding, fynbos habitats in much of the central Cape Fold Belt are subject to aggressive invasion by alien plants (pine and hakea) which threatens large-scale habitat transformation and degradation (Cowling et al. 2009). The potentially distinct western lineage appears to be restricted to isolated forest patches of limited extent and is likely to meet the criteria for red-listing on account of its narrow range, should this eventually be shown to be a distinct taxon.
[FIGURE 64 OMITTED]
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|Title Annotation:||Revision of the larger cannibal snails (Natalina s. l.) of southern Africa--Natalina s. s., Afrorhytida and Capitina (Mollusca: Gastropoda: Rhytididae)|
|Author:||Herbert, D. G.; Moussalli, A.|
|Date:||May 1, 2010|
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