212 Land and Fresh~watcr Sheik of the Himalaya. [March, 



It is interesting to observe the wide distribution of these tender 

 beings, and to trace the gradual and almost insensible yielding of one 

 species to another as the elevation or the climate varies. The shells 

 of our lowland provinces, for descriptions of which we are chiefly in- 

 debted to Mr. Benson, here give place, as the temperature becomes 

 cooler, to forms more nearly resembling those of Europe, some still ad- 

 vancing a short way into the hills, but impatient of the chills of our 

 mountain winters, confining themselves to the valleys of the lower ranges 

 around Subathu. 



One species, however, the " Nanina vesicula" described by me as 

 " Helix 29" in the third volume of the Asiatic Society's Journal, as 

 occurring between Neemuch and Mhow, and since discovered by Mr. 

 Benson in the Rajmahl range, seems alike to defy the heats of the 

 provinces and the winter of the hills, ascending even beyond the height 

 of 10,000 feet above the sea. It ranges therefore over the central and 

 western tracts of this presidency, and occurring in profusion along the 

 verge of the hills at Mansir Debi, mounts to Subathu, Simla, and 

 Hattu mountain, preserving everywhere the same habits, creeping 

 over every plant and shrub during the rains, and concealing itself 

 beneath stones and at the roots of trees, with the aperture closed by an 

 unattached calcareous operculum. From its occurring on Hattu, it is 

 probable that it may be met with at inferior elevations throughout this 

 portion of the hills. 



Another species, the " vitrinoides" of Deshayes, inhabiting the 

 Rajmahl range, and extending also to the western frontier, advances 

 upwards only to Subathu, and its neighbouring valleys, passing at 

 Simla into a strong variety possessing the same form, and partaking of 

 the same habits and general economy. 



" Succinea crassiuscula," (Benson,) has also a wide range and is appa- 

 rently to be met with throughout the provinces, occurring abundantly, 

 according to Mr. Benson, in the compound of the Asiatic Society's 

 Rooms in Calcutta, extending through Bahar and Allahabad to the 

 western frontier, and advancing to the hills as high as Subathu, 



With the exception of " Nanina vesicula' the shells we are about to 

 describe, appear to be peculiar to these hills, differing in toto from those 

 of the Sylhet collection, yet with them forming that beautiful connec- 

 tion, which is seen to pervade all nature. 



In giving Subathu as the probable boundary beyond which the 

 species of the provinces do not occur, it must be borne in mind that 

 I would be understood to mean, not that they are never found more in 

 the interior of the hills, but simply that they do not rise to a greater 



