n 



Description of Camptoceras. 467 



Testae spira elongatiuscula, apertura obliqua, ovata, integra, superne 

 angulata; peristomate continuo, subreflexo ; anfraectu ultimo subum- 

 bilicato. 



Animal. Melanise simile, proboscide elongata, antice emarginata, ten- 

 taculis filiformibus duobus oculos postice prope basin gerentibus ; pede 

 mediocri ovato, antice subquadrato. Operculo corneo subspirali. 



T. Montana. Testa olivacea ovato-conica, anfractibus sex rotunda- 

 tis, suturis impressis, apertura intus albida, peristomate nigrescenti ; 

 apice obtuso, plerumque decollato. 



Hab : In rivo, apud lacum Kunavurensem Bhimtal dictum. 



This little shell I first found adhering to the prone side of a floating 

 leaf of a species of Potamogeton, in a clear and weedy stream running 

 through a marsh at the head of Bheemtal, and supplying that lake; 

 and subsequently Dr. Bacon and myself found it abundantly on the 

 stems of a water Iris which we drew up by the roots, from the bed of the 

 stream for examination. Accompanying it I discovered a few specimens 

 of a shallow Ancylus,* and of Planorbis Calathus,f of which Dr. Bacon 

 had observed dead specimens under stones, in the marsh between the 

 old Buddhist temple and the lake. Among the roots were also a species 

 of Pisidium, and a single dead specimen of a large and delicate Succinea, 

 very similar to the European S. Pfeifferi, and nearly related to a species 

 taken in Afghanistan by Capt. Hutton. 



Tricula appears to connect the genus Paludomus of Swainson, (con- 

 sisting of Melania conica, M. Stephanus,J &c.) with the more typical 

 Melaniae. It resembles the former in its thickened inner lip, while by 

 the proportion of the spire to the aperture, and in its decollated apex it 

 approaches some of the types of Melania. Again, its affinities shew a 

 tendency towards Paludina in form ? and in the continuity and incrassa- 



* This is the second species observed in India. Capt. Hutton found an 

 unique specimen of another species some years ago at Bolundshehr, in the Doab 

 of the Ganges and Jumna. 



f Nearly related to a species found in Bengal by Dr. Cantor, and to another 

 species from Chusan. It is however easily distinguished by the circumstance of 

 its being furnished interiorly with series of toothed ridges at irregular intervals. 

 A similar, but more regular structure, has caused several Naturalists to describe the 

 European species P. lineata, under the generic name of Segmentina, after Dr. 

 Fleming. I have elsewhere (Chusan Shells) adduced reasons for rejecting that 

 supposed genus. The structure of the species under consideration will tend to 

 confirm them. 



t Jour. As. Soc. vol. v. page 747. 



