Prestonella Connolly, 1929

Herbert, D. G., 2007, Revision of the genus Prestonella (Mollusca: Gastropoda: Orthalicoidea: Bulimulidae s. l.), a distinctive component of the African land snail fauna, African Invertebrates 48 (2), pp. 1-19 : 5

Genus Prestonella Connolly, 1929

Prestonella: Connolly 1929: 232 . Type species (original designation): ‘ Buliminus bowkeri ’ [sic] Sowerby, 1890.

Diagnosis: Shell succineiform to elongate-conical, thin; peristome obliquely tangential, lacking dentition or labral thickening; umbilicus patent but partially concealed by reflected columella; protoconch steep-sided and roundly angular, frequently with more or less straight axial riblets and finer spiral threads; teleoconch sculptured with uneven growth-ridges and sometimes with spiral threads, producing a fine, uneven granulation/ reticulation on spire whorls; teeth in central portion of radula monocuspid; jaw stegognathous. Distal reproductive tract relatively simple; penis complex long, including an epiphallus and flagellum; penis retractor muscle short, attached to tip of flagellum; duct of bursa copulatrix long; no other accessory appendages or glands.

Distribution ( Fig. 1 ): Endemic to southern Africa; known only from south-western Lesotho and along the southern edge of the Great Escarpment in South Africa, 1000– 1750 m a.s.l.

Figures

Fig. 1. Distribution of Prestonella. The genus is endemic to southern Africa, occurring in south-western Lesotho and along the southern edge of the Great Escarpment in South Africa (1000–1750 m a.s.l.); contour at 1000 m, showing approximate position of Great Escarpment.