134 



LAND AND FRESH- WATER SHELLS OF X. A. [PART II. 



Fi^. 225. 



Haldeman considers PI. elevatus a synonym of this species. 

 No. 8509 of the collection was labelled by J. G. Anthony Fl. 

 concavus, a name occurring in catalogues, but not described. I 

 have no doubt of its identity with this species. No description 

 was ever published, as Mr. Anthony informs me, owing to the 

 doubts of its being distinct. The original description and figure 

 of Fl. elevatus are given below. 



Planorbis elevatus. — Shell horn-color, finely striate ; whirls four, as high 

 as wide ; last whirl well rounded, very distinctly carinate below ; inclina- 

 tion to the left about 48° ; right side convex, flattened at the apex ; left 

 side very deeply concave ; suture deeply impressed ; aperture 

 round-ovate, large, with its upper extending much beyond its 

 lower margin. Greatest breadth .17 inch, least breadth .13 

 inch, height .06 inch. Cabinets of Bost. Soc. N^t. Hist., of 

 Middlebury College, of S. S. Haldeman, of Marietta, Pa. ; of 

 J. G. Anthony, of Cincinnati, and my own. 



Habitat. This species was discovered in the summer of 1838, 

 in a small spring in a rocky cavity, in South Boston. Kearly 

 a hundred specimens were obtained, and a much larger num- 

 ber were left. Visiting the same spot a few days since (July, 1S40), I found 

 the spring filled up with stones to the top of the water, and not a shell to 

 be seen. Last summer I obtained a specimen in Lake George, N. Y. Dr. 

 Wm. Prescott has found the species in Lynn. 



This species much resembles P. parvus, Say, and for some time I doubted 

 whether it was distinct. But the specimens uniformly differ from that 

 shell in having the spire elevated above the plane of the last whirl, whereas 

 in that species it is concave, and consequently this species is much more 

 deeply umbilicated on the left side ; also, that species is distinctly carinate 

 on the middle of the last whirl, but is very indistinctly carinate below the 

 middle, if at all. (Adams.) 



Planorbis 

 tlevat (W. 



