MOLLUSCA OF SOUTH AFRICA. 
(PELECYPODA,) 
BY 
G, B.. SOWERBY. BES. 
Among a large quantity of Pelecypoda submitted to me by 
Dr. J. D. F. Gilchrist, Government Biologist of the Cape Colony, 
are some species of special interest. Thirty-three I am describ- 
ing as new to science, and noting a few others which have not 
hitherto been recorded as South African. Among the former I 
may specially mention 4 new species of Poromya, Forbes, a very 
rare and remarkable genus, of which no species has hitherto 
been recorded from South African waters; 4 new species of 
of Cuspidaria, Nardo (Ne@ra, Gray), of which genus only one 
species (C capensis, Smith) had been noted as South African, 
five new species of Crassatella, Lamarck, and three of Nuculana, 
Link (Leda, Schumacher). 
Among the species already described, but not as South 
African, the most interesting, is a fine specimen Cryptodon 
investigatoris, Smith, obtained in deep water off Cape Point. 
Fam. Pectinide. 
*CHLAMYS GILCHRISTI, n. sp. (Plate VI., fig. 6). Shell nearly 
orbicular, equivalve, thin, semitransparent, compressed, pale 
pinkish yellow ; auricles unequal, the posterior the smallest. 
Left valve very slightly convex, rayed with about nine very 
slightly raised ribs, about 70 slightly imbricated riblets or lire, 
and numerous very close rough intervening striz; anterior 
auricle rather broad, rectangular, with six narrow rather 
prominent ridges, crossed by foliated lamelle, the interstices 
being peculiarly corrugated ; posterior auricle smaller, more 

* Chlaniys, Bolten, 1798 (Pecten, Auctorum). 
