603 
XXXV. On the Specific Identity of the described Forms of Tanalia. By Henry F. 
Blanford, Esq. Communicated by Dr. Joseph Hooker, F.B.S., F.Z.S., 8fc. 
Read June 19th, 1862. 
ANY naturalist who has looked through the list of land and fresh-water Mollusca in 
Sir Emerson Tennent's work on Ceylon can scarcely fail to have heen struck with the 
large number of species there enumerated which are peculiar to the island, especially in 
the case of such genera as Aulopoma, Cataulus, Tanalia, and Bh'dopotamis, the generic 
range of which is almost equally restricted. The area inhabited by most of these peculiar 
forms is, indeed, limited to less than half that of the entire island : the plains of the 
eastern, northern, and north-western provinces possess a fauna in a great measure 
identical with that of the Central and Southern Carnatic — e. g. Helix vittata, H.fa/lo- 
ciosa, H. bistrialis, H. Tranquebarica (type, and var. semirugata), Bulimus Mavortius, 
B. ptmctatus, the wide-ranging B. pullus and B. gracilis, Cyclophorus involvuh'*, and 
several freshwater shells ; and the genera above quoted, with numerous peculiar forms 
of Helix, are restricted, with a few exceptions, to the hills of the central province and 
to the undulating, wet, forest-clothed country to the south and south-west. It is true 
that the apparently endemic character of this fauna may in some cases be rather apparent 
than real, owing to our ignorance of those neighbouring stations the climatal conditions 
of which most resemble those of South-western Ceylon. The very different physical con- 
ditions of the northern provinces, on the one hand, and of the hills and south-western 
parts of the island, on the other, would lead us to expect, a, priori, the existence of a 
distinct and much richer Molluscan fauna in the latter ; and the hills and west coast 
of the southern extremity of the Indian peninsula, the damp jungles of which present 
conditions very similar to those of Southern Ceylon, have been too little searched by con- 
chologists to admit of anything like a fair comparison of the faunas. The little that we 
do know, however, of the pulmoniferous Mollusca of the Travancore Hills * and of the 
Anamullies f indicates an affinity with those of the Mlgiris, which are at least equally 
well worked out with those of Ceylon, and which include but two species {Bulimus Nilagi- 
ricus, Pfeiffer, and Achatina Ceylanica, Pfeiffer) hitherto identified as common to the 
hills of Ceylon, with the exception of such low-country species as range through the 
intermediate plains and ascend the lower slopes of the hill-ranges. It seems, therefore, 
improbable that future discoveries will go very far to diminish the number of forms the 
ran-e of which is restricted to Southern Ceylon ; and we have before us the apparently 
* Benson, Ann. Mag. Nat. Hist. 1861, vol. vii. p. 81. 
f Mr. King's collection of shells from these hills was unfortunately 
™*i™„ v.nnra^ar flip iihnvp inference is drawn. 
From his commu- 
