NEW FRESH WATER AND LAND SHELLS. 173 



them to Mr. Say for description. They certainly do not appear to me to be 

 the same, although in many characters they agree. The animal of occidentalis 

 I have not seen; the operculum is spiral; at present I prefer to place it among 

 the Melania. Some of the varieties before me are very beautifully furnished 

 with raised revolving striae. When there is a single one, it gives the shell the 

 appearance of being carinate, as it appears near the centre of the whorl. In 

 some specimens these strise are more numerous; in a single one I have counted 

 fifteen. There appear to be no bands on the outside, but sometimes purple 

 lines on the inside mark the places of the exterior striae. There is generally 

 more or less colour in the interior and about the columella, the base of which 

 is disposed to be angular. The aperture is nearly three-fourths the length 

 of the shell* 



Melania Niagarensis. Plate 5, Fig. 21. 



Testa l<Bvi, obtuso-conicd, crassd, cornea; spird brevi; suturis linearibus; anfractibus subplanulatis ; 

 aperturd subgrandi, ellipticd, intus purpured. 



Shell smooth, obtusely conical, thick, horn-coloured; spire short; sutures linear; whorls rather flat; 

 aperture rather large, elliptical, within purple. 



Hab. Falls of Niagara. 



My Cabinet, and Cabinet of P. H. Nicklin. 

 Diam. .25, Length .55 of an inch. 



Remarks. — I obtained this shell many years since at the foot of the falls of 

 Niagara, where it exists in abundance. It may generally have been confounded 

 with M. depygis, Say. When I procured it, I placed it in my cabinet under 

 that name with a mark of doubt. It is a smaller shell than the depygis, has a 

 shorter spire and a narrower aperture. This species has a purple columella 

 and interior, which in some cases are very dark. The specimens procured 

 were all more or less eroded, and the apex removed. The number of whorls 

 is either six or seven. The aperture is nearly half the length of the shell. 



* Since the above was written, I have seen in the "Boston Journal of Science," the description and 

 figure by Mr. Anthony, o? Anculotus costatus which in some respects answers to this shell. Mr. A. says 

 that his shell has "about five costse revolving around it." 



