1866.] Contributions to Indian Malacology. 145 
No. 25.—Unio occatus, Lea. Bengal. 
Lea, Jour. Acad. Nat, Sci. Phil. 2nd Ser. V. 398, Pl. 50, fig. 304. 
A compressed form, with strong teeth, fairly intermediate between 
ceruleus and favidens, and allied to U. macilentus, Bs. and U. plagio- 
soma, Bs. but more compressed than either. It especially requires 
comparison with U. macilentus, of which it may be a compressed form. 
No. 26.—Unio Gerepipont, Hydoux. Coromandel. 
Said by Lea to be the same as Unio ceruleus. 
No. 27.—Unio Bonneavnt, Hyd. South India. 
No. 28.—Unto Gavpicuavni, Hyd. Bengal. 
No. 29.—Unto Keravprenn, Hyd. Chandernagore. 
IT am indebted for all my information as to the above four species 
to Mr. Benson. I have not access at present to the work in which 
they are described. 
In Kister’s monograph of Unio in Martini and Chemnitz another 
species is described from the “‘ Hast Indies,”’ U. Hxanthematicus, Kister, 
p. 248, pl. 81, fig. 2. The authority, however, for the locality is Dr. 
v. d. Busch, whose general accuracy, after the instances given above, 
may be open to doubt; the ‘‘ Hast Indies” in a Natural History sense, 
not many years since, denoted any country between Africa and 
Kamschatka, and the peculiar pustulated surface of the shell, from 
which the name is derived, is unknown in any Indian species. I 
think it is probably not a native of the Indian Peninsula. 
U. discus, Lea, Trans. Am. Phil. Soc. IV, 74, Pl. 18, 7. 57, was at 
first stated to be from India, on, however, palpably insufficient 
grounds, the original specimen having been purchased from a dealer 
amongst a lot of shells from India. The shell is so distinct from any 
known Indian species, that I had concluded that the locality was 
assigned to it in error, before I found that in a subsequent volume of 
the Trans. Am. Phil. Soc., Vol. VIII, p. 234, note, Lea mentions 
his having ascertained that the locality was the River Moctezuma in 
Central America. 
Mr. Benson mentions (Ann. and Mag. Nat. Hist. 1862, X., 195,) 
his having received from the Malabar Coast a shell which he refers to 
U. consobrinus, Lea, 
