and on a Travancore Batissa and Himalayan Tricula. 415 



while its construction is also likely to be unguiculate. There is 

 some resemblance in this shell to Neritina, for which genus a 

 specimen might, on a cursory glance, be taken. The upper part 

 of the columellar callosity exhibits in some specimens a blackish- 

 brown tint, and a patch of the same colour may occasionally be 

 observed at the base, in the interior of the aperture, the throat of 

 which is tinged with violet and purple and presents a minutely 

 corrugate surface. 



Since the publication of Corbicula Quilonica, Bens., in the 

 Ann. Nat. Hist, for October 1860, where it was described from 

 young specimens, I have received from Capt. C. A. Benson a 

 single large and solid example, found at the same place. It 

 belongs to Gray's Batissa, a genus intermediate between Corbi- 

 cula and Cyrena. The shortness of the serrulate lateral teeth 

 was recorded in the Latin characters, and alluded to, as well as 

 their comparative brevity on the anterior side, in the subsequent 

 remarks as worthy of notice. The continent of India had not 

 previously furnished any examples of Batissa, of which some fine 

 species inhabit the Eastern Archipelago. 



The following are the dimensions of the adult shell : — 



Long. 21, lat. 34, diam. 15 mill. 



In the original description of the young, the breadth was 

 by mistake stated as 10 instead of 8 mill., and the length as 

 8 mill, instead of 10. 



I am informed that the conchological writer, M. Brot, has, 

 in his Catalogue of Melaniadse (a copy of which has not yet 

 come under my inspection), referred my minute Melaniadous 

 Tricula, from the Himalaya, to the genus Paludina. M. Brot 

 can scarcely have examined the subspiral operculum of the shell, 

 or consulted the original description published in M'Clelland's 

 'Calcutta Journal of Natural History ' for 1842; otherwise he 

 would not have overlooked the differences presented by such an 

 operculum from the concentric laminations of that of Paludina, 

 the animal of which differs altogether from that of the mountain 

 form, which nearly approaches that of Melania ; while the shell 

 of Tricula bears the same relation to Melania as that observable 

 in the Egyptian and Syrian Paludomus bulimoides, Olivier, 

 when compared with the more Eastern forms of the genus. 

 Tricula occurred at an altitude of 4000 feet. It may now possi- 

 bly inhabit the plains, as I placed living specimens in a pond at 

 Moradabad. 



I add an extract from the paper in the Calcutta Journal : — 



" Subgenus Tricula. 

 " Testae spira elongatiuscula ; apertura obliqua, ovata, integra, su- 



