Afrodonta farquhari ( Burnup, 1912 )

Herbert, David G., 2020, Revision of the aperturally dentate Charopidae (Gastropoda: Stylommatophora) of southern Africa - genus Afrodonta s. lat., with description of five new genera, twelve new species and one new subspecies, European Journal of Taxonomy 629, pp. 1-55 : 8-9

Afrodonta farquhari ( Burnup, 1912)

Figs 1 G–J, 3, 17E–F

Endodonta [ Endodonta (Afrodonta) ] farquhari Burnup, 1912: 339 , pl. 24, figs 7–10.

Endodonta (Afrodonta) farquhari – Connolly 1912: 128.

Afrodonta farquhari – Connolly 1933: text-fig. 1(3); 1939: 253, text fig.19(3). — Solem 1970: 351. — Herbert & Kilburn 2004: 251, text-fig.

Diagnosis

Shell very small, spire distinctly raised; protoconch smooth, at most microscopically shagreened (diameter ±360 μm); teleoconch texture silky; sculpture comprising simple, very fine and close-set axial riblets, tending to alternate in strength; spiral sculpture of fine threads in riblet intervals; parietal region with two well-developed, in-running lamellae; baso-columellar region with a recessed in-running ridgelike denticle; palatal region with three in-running lamellae at and below mid-whorl, a fourth smaller and narrower one just below insertion of outer lip; umbilicus relatively narrow. Shell honey-coloured to brown when fresh; diameter up to 1.5 mm.

Material examined

Holotype

SOUTH AFRICA • E. Cape, Grahamstown ; prior to 1912; J. Farquhar leg.; NHMUK 1912.3.25.3 .

Burnup (1912) cited Grahamstown as the primary locality for this species and referred to ‘the type’ in the legend to his illustration of the species. Since he also stated (p. 343) that ‘the types of all new species will be placed in the British Museum’ and this is the only contemporary NHMUK material from Grahamstown collected by J. Farquhar, I follow Solem (1970) in considering it to be the holotype.

Paratypes

SOUTH AFRICA – E. Cape • 3 specimens; Port Elizabeth ; J. Farquhar leg.; NMSA 2605/T612 • 3 specimens; same collection data as for preceding; NMSA A9217/T2181 • 5 specimens; Port Alfred ( Kowie ); J. Farquhar leg.; NMSA 2604 /T612 • 1 specimen; Bathurst, Trappe’s Valley ; J. Farquhar leg.; NMSA A9215 /T2179 • 4 specimens; same collection data as for preceding; NMSA A9216 /T2180 .

Distribution and conservation

Widely distributed in south-eastern South Africa ( Fig. 3 ), ranging from Cape St Francis in E. Cape to the border between of KwaZulu-Natal and Mozambique, almost certainly extending into coastal southern Mozambique, though not as yet recorded there; at altitudes of up to approx. 500 m a.s.l., rarely recorded far from the coast (furthest inland – Grahamstown and Hluhluwe); living in sandy leaf-litter, primarily in dune forest and coastal bush, but occasionally in lowland and scarp forests. Not of conservation concern.

Remarks

This species is closest to Af. novemlamellaris , but has fewer palatal lamellae and a weaker basocolumellar denticle. In Af. novemlamellaris the last adult whorl is also proportionately deeper. Afrodonta farquhari largely replaces Af. novemlamellaris in coastal habitats and the species rarely co-occur at precisely the same locality.

Figures

Fig. 1. Shells of Afrodonta species. A–C. Af.bilamellaris Melvill & Ponsonby, 1908, Karkloof, KwaZulu- Natal, diameter 1.45 mm (NMSA W8721). D–F. Af. connollyi Solem, 1970, Middledrift, Thukela Valley, KwaZulu-Natal, diameter 1.52 mm (NMSA V4985). G–J. Af. farquhari (Burnup, 1912), Gamtoos River mouth, E. Cape, diameter 1.39 mm (NMSA W8688). K–N. Af. geminodonta sp. nov., holotype, diameter 1.36 mm (NMSA V9891/T4241).

Fig. 3. Distribution of Afrodonta farquhari (Burnup, 1912) (orange triangles) and Af. novemlamellaris (Burnup, 1912) (blue squares). The distribution of Af. novemlamellaris continues north into Malaŵi. Contour at 1000 m.