1866.] Contributions to Indian Malacology. 141° 
- No. 10.—Unio Brneatensts, Lea. Bengal. 
Lea, Trans. Am. Phil. Soc. VI. 3, pl. 2, f. 3. 
Kister, Mart. and Chem., p, 228, pl. 77, f. 2, 3. 
Tn this case again, two totally distinct shells are figured, and again 
the authority for Kiister’s appears to be Dr. von dem Busch, whose 
collection furnished the specimen figured in Martini and Chemnitz. 
hea’s type is a very peculiar variety of U. marginalis, very much 
“longer” (that is wider when measured from the umbones to the 
ventral margin) in proportion to the breadth than usual. I have not 
met with it. It was obtained by Lea from Dr. Burrough who pur- 
chased it in Calcutta, and believed that it inhabited the Ganges, It 
has better claims to distinction than most of Lea’s ‘ species.’’* 
Kister’s type is a much thicker, more tumid shell, with far 
stronger teeth and impressed cicatrices, much more inequivalve and 
different in almost every character. I cannot recognise it as any 
form with which I am acquainted, and I much doubt its being Indian 
at all. At all events it is nearer to U. corrugatus than to U. mar- 
ginalis. 
No. 11.—Unto tamettatus, Lea. Bengal. 
Lea, Trans. Am. Phil. Soc. VI. 19, pl. 6, f. 16. 
This is another variety of the U. marginalis type, perfectly inter- 
mediate between the two last named, and approaching the type more 
nearly than either. Lea’s shells were probably immature. In the 
younger shells of marginalis, the hinge teeth are more lamellar than 
in the adults, and the principal character of this “ species” and of the 
two preceding is the lamellar teeth. 
IT have not met with the exact type of this shell, but it doubtless 
inhabits the neighbourhood of Calcutta. Specimens resembling it in 
every way except in being rather less long Qn the dorso-ventral dia- 
meter) in proportion to their breadth are common. 
No. 12.—Unio Rasanensts, Lea. Rajah’s Tank, Calcutta. 
Lea, Trans. Am. Phil. Soc. VIII., 239, pl. 23, fig. 53. 
The above is the locality quoted. Jam unable to discover what 
*In a letter to my brother, Mr. Benson suggested a doubt as to whether 
this species were Indian. Taking into consideration the circumstance that 
nearly all the shells in the Calcutta bazar are foreign, this suggestion appears 
highly probable. 
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