Notes on South African Mollusca. 177 



dimensions are: Diam. maj. 21, min. 17'3 ; alt. max. 15-8; apert. 

 11 3 x 9-3 mm. 



Two specimens, labelled " Namaqualand," in the Layard Col- 

 lection. I am uncertain whether they can be the pair mentioned 

 as from Namaqualand on p. 146, or whether they are not rather the 

 small form of lacanus from Bredasdorp (p. 158). Under such cir- 

 cumstances, it seems inadvisable to name them. 



4. DORCASIA ALEXANDRA var. (S.A.M. No. A 2819). 



Shell similar to the typical form in all respects except the 

 sculpture, which, though much worn, appears to be slightly more 

 pronounced, and the umbilicus, which is very wide and open, deep 

 and perspective, extending to the transparent apex. 



Diam. maj. 28'1, min. 22-8 ; alt. max. 14-2 ; apert. 15 x 11 mm. 



Animal unknown. 



Hab. DAMABALAND. Erongo Mountains (Eogers). 



A connecting link between the var. perspectives, which it resembles 

 in its open umbilicus, and the typical form, which it nearly resembles 

 in sculpture. The locality, however, being just north of the Omaruru, 

 suggests that it is a smoothish sub-variety of pcrspectiva, rather than 

 a widely umbilicate one of the true alexandri. 



5. HELIX BULBUS, Menke. 



1848 Helix bulbus, Mke., Pfr., Zeitschr. f. Malak. v. p. 116. D. 

 1853 ,, Conch Cab., p. 268. PI. CXXII (1852), 



f. 4-6. D.F. 



Apparently founded on a single specimen, whose present where- 

 abouts cannot be traced. 



A translation of Pfeiffer's diagnosis runs: "Shell moderately 

 umbilicate, globose-depressed, thin, irregularly rugose and sculp- 

 tured with impressed concentric lines ; white ; spire flattish. 

 Whorls 4i-, almost flat, the last rounded, scarcely descending in 

 front. Aperture oblique, lunate-oval, interior white, shining ; peri- 

 stome simple, margins approximating, the right lip straight, curved 

 forward ; the basal very slightly reflexed ; the columellar margin 

 dilated. Shell 26 x 21 ; alt. 13 mm." 



" Hab. CAPE, in coll. Menke." 



The description and figure should be quite sufficient for the 

 identification of the species, should it ever be rediscovered. Not 

 only, however, do the conspicuous spiral striae suggest little affinity 



