Japanese Species of the Genus Corbiada. 
5^9 
very poor, and give a very wrong idea of the sh^ape of the species. Kobelt's figure is 
only a copy of Reinhardt's and Clessin's figures, as is often the case, represent anything 
but the shells figured. 
The shells of this species are not, as one would be inclined to believe from an 
examination of Reinhardt's figure, trigonal, but are much less higher than long ; 
Reinhardt's description of " langlich rund " is much more applicable. This is the 
smallest of the Japanese Corbiculas, the largest specimen before me being only I4mni. 
long ; Reinhardt's largest specimen was i6mm. long. The shell for this group of 
small-sized Corbiculas is rather stout, and has a fairly strong hinge. The surface is 
sculptured with strong, regular and concentric striae, which are separated by wide 
interspaces. I have nothing further to add to the original description of the species 
by Reinhardt. 
Relationships : — The species, with its form awajiensis, is quite distinct from any 
other of the Japanese Corbiculas, and is probably related to some of the smallest forms 
found on the mainland. 
var. awajiensis (Pilsbry). 
(Plate XXII, fig. 19.) 
igoi. Corbicula awajiensis, Pilsbry, op. cit.. p. 407. 
1907. Corbicula awajiensis, Pilsbry, op. cit., p. 159, pi. vii, figs. 13, 14. 
This form was figured in the second paper cited above, but Pilsbry did not add 
anything further to his first description. I have seen a paratype kindly sent me by 
Dr. Pilsbry and two other specimens from Awaji Island — the type-locahty — and can 
see no reason for distinguishing it as specifically distinct from C straminea. The only 
differences between the two are the slightly more elongate form and the little weaker 
hinge ; the sculpture in both cases is identical. It is probably a dwarfed or depau- 
perated form of straminea, and until more material is available for study I propose 
treating it as a distinct variety. 
