Alvania proditoris (Thiele, 1925) n. comb.

(Figs 3; 48)

Rissoa proditoris Thiele, 1925: 80, pl. 6, fig. 9.

TYPE MATERIAL. — Lectotype. South Africa • dd; Valdivia Stn 101; 33°50’27”S, 25°48’46”E; ZMB/Ma.64965 (here designated). Paralectotypes. South Africa • 5 dd; Valdivia Stn 95; 34°51’0”S, 19°37’47”E; 80 m; ZMB/Ma.64965 • 3 dd; Valdivia Stn 101; 33°50’27”S, 25°48’46”E; ZMB/Ma.64965 .

Angola • 1 dd; Valdivia Stn 81; 16°26’27”S, 11°41’27”E; ZMB/ Ma.64965 .

TYPE LOCALITY. — South Africa, Valdivia Stn 101; 33°50’27”S, 25°48’46”E.

DISTRIBUTION. — Only known from southern Africa (Valdivia Stns 95 and 101) and from a station in southern Angola (Valdivia Stn 81) (Fig. 48).

DIAGNOSIS. — Alvania with small (height <3 mm), robust shell, ovate-conical; spiral sculpture stronger than axial; aperture piriform, peristome continuous and simple, outer lip with robust; umbilical fissure absent. Protoconch paucispiral, dome-shaped, with spiral sculpture. Colouration uniform whitish.

REMARKS

The lot from southern Angola (Valdivia Stn 81) comes form a completely distinct biogeographic area, and we are not sure it is not a case of mislabelling. In any case, to stabilize the type locality we have designated as lectotype a specimen from the Cape area (Valdivia Stn 95). Rissoa proditoris Thiele, 1925 is clearly a member of Alvania, with its shell devoid of umbilical fissure, with double sculpture (axial and spiral), piriform aperture, continuous and simple peristome, outer lip with robust varix, dome-shaped paucispiral protoconch with spiral sculpture. We accordingly propose Alvania proditoris (Thiele, 1925) n. comb. as a new combination for Rissoa proditoris Thiele, 1925 .