448 Mr. W. T. Blanford on the Classification of 



the whorls of the operculum there is some resemblance to the 

 West-Indian Choanopoma ; but the shells are very diflferent. It 

 forms an additional link between the Indian fauna and that of 

 Africa and South-western Asia*. 



6. Jerdonia, W. Blanf. 



Testa umbiUcata, pyramidata, cornea. Operc. concentricum, 

 arctispirum, sulco marginali circumdatum, duplex ; interne mem- 

 branaceum, externe testaceum, et ex anfractibus vittseformibus com- 

 positum, quoque proximi interioris marginem externum tegente. 



Type, /. trochlea, Bens., sp.. 



Although I proposed this genus two years ago (Journ. Asiat. 

 Soc. Bengal for 1861, vol. xxx. p. 351), I have never published 

 the characters in full. The species upon which it is founded is 

 a peculiar minute, pyramidal, horny, tricarinated shell inhabiting 

 the Nilgiri Hills, and which, in the absence of the operculum, 

 was referred by Dr. Pfeiffer (Mon. Pneum. Viv. Supplement, 

 p. 116) to Cyclostoma. The operculum I obtained in 1859, 

 and it proved to have the peculiar structure described above f. 

 It bears no inconsiderable resemblance to that of Cyclotus varie- 

 gatus, Sw., differing mainly in the inner edge of each whorl 

 resting upon the outer edge of the next, whereas in Cyclotus, 

 and in general throughout the Cyclophorida, the reverse is seen. 



The position of this peculiar shell is still somewhat obscure ; 

 but as the operculum is, despite its singular structure, more 

 nearly allied to that of Cyclotus than to any other, it may, in 

 default of a knowledge of the animal, be classed with the Cyclo- 

 phorinee, and may possibly be related to the next genus. 



In the paper above referred to as published in the ' Journ. 

 Asiat. Soc. of Bengal,' I was disposed to refer a second species, 

 from the Kolamully Hills of South India to this genus. Fur- 

 ther examination of this form, the operculum and animal of 



* Throughout the fauna of the Indian peninsula there is a blending of 

 Africano- Asiatic and of Malayan forms. In the Mammalia, amongst the 

 Carnivora are found species of the African Lion and Hyaena, and the Cauca- 

 sian Wolf, Fox, and Jackal, with the Malayan Tiger, Paradoxure, &c. ; and 

 in the Ruminantia, the African types in the Indian forms of Antelope, 

 with the Malayan Rusa- and Axis-deer and Bos gaurus. Amongst the 

 birds the same is seen, — species of the Malayan Jungle-fowl and Peacock 

 co-existing with those of the African Sand-grouse and Francolin. In the 

 land-shells, Malayan types of Nanina, Cyclophorus, &c., accompany 

 African forms of Bulimus, Otopoma, &c. As might be expected, the 

 African representatives predominate in the west of the peninsula, Malayan 

 in the east ; and the former frequently occur on the plains, the latter on 

 the hills, the fauna of which often resembles the Malayan types of the 

 Himalayas. 



t It is figured in the illustrations to the paper in the ' Journ. As. Soc. 

 Bengal ' above referred to. 



