148 Contributions to Indian Malacology. [No: 2, 
No. 39.—Unto Tuwartzst, Lea. Ceylon. 
Lea, Jour. Acad. Nat. Sci. Phil. 2nd Ser. IV., 246, pl. 37, f. 125. 
This shell only differs from the last in having a rather straighter 
hinge line, and being slightly more inequilateral. If such differences 
‘species’ might be manufac- 
are to rank as specific, half a dozen 
tured out of any tank in Calcutta. The separation of these two forms 
is perfectly unjustifiable in a genus like Unio. 
The above are the only species that I can trace specially described 
from Ceylon. Lamarck’s variety 6. of Unio marginalis described as 
var. testé minore, breviore, and 75 millimetres broad was also from 
Ceylon (iam. VI. 79). Sir Emerson Tennent, in his work on Ceylon, 
enumerates only U. corrugatus besides U. marginalis. He, however, 
adds that Mr. Cuming possessed six species from the island, which 
had been sent to Mr. Lea. U. Thwaztesii and U. Layardi are doubt- 
less two of these, as they were from Mr. Cuming’s cabinet, but no 
mention is made of the others by Mr. Lea. 
IV.—Borma. 
No. 40.—Unito Tavoyensts, Gould. Tavoy. 
Gould, Proc. Bost. Soc. Nat. Hist. I., 140. 
» Ot. Conch, p. 190. 
Kiister, Mart. and Chem., p. 166, pl. 48, f. 2. 
“Closely allied to U. corrugata, Lam. which is less rounded and 
less corrugated” (Gould, 1. c.) More nearly allied to Lamarck’s than 
to Chemnitz’s type of U. corrugatus. Kiister’s figure agrees well with 
Gould’s description, but represents a young shell, not mature. The 
specimen figured was from the collection of Dr. Sturm (and not from 
that of Dr. v. d. Busch). 
No. 41.— Unio crispatus, Gould. Tavoy. 
U. crispata, Gould, Proc. Bost. Soc. Nat. Hist. I,, 141. 
” ry) Ot. Conch. p. 191. 
No. 42.—Unio rouiacnus, Gould. Tavoy. 
U. foliacea, Gould, Proc. Bost. Soc. Nat, Hist. I, 141. 
Ot. Conch. p. 191. 
29 2) 
An ally (variety?) of U. marginalis, Lam. “ Closely allied to U. 
Bengalensis and Corrianus, Lea.’”’ (Gould, 1. c.) 
