THE NAUTILUS. 



Vol ~ x. AUGUST, 1896. No. 4 



A NEW SPECIES OF POMATIOPSIS. 



BY HENRY A. PILSBKY. 



The genus Pomatiopsis is peculiar to North America. All of the 

 species occur in the temperate portion of the continent, and the 

 whole United States, excepting perhaps parts of the Koeky Mount- 

 tain region, still but imperfectly explored for small shells, is occupied 

 by the various forms. The best-known species P. lapidaria Say, is 

 as much a terrestrial mollusk as most of the Succineas. They can- 

 not live for any length of time immersed in water, and I have 

 drowned specimens, just as laud snails may be drowned, by confin- 

 ing them in a vessel full of water. Information upon the other 

 species is less definite, but P. cincinnatiensis at least seems to be of 

 aquatic habits. 



The genus is much more distinct than most genera of Amiticolidce, 

 the dentition being, as William Stimpson first pointed out, strikingly 

 characteristic of the group. The shells vary from the high, turrited 

 Bythinella form, to nearly as short as some Amnicolas. 



The species described below is the third from the Eastern States, 

 and the fourth species of the genus, the others being P. lapidaria 

 Say, P. cineinnatiensis Lea and P. intermedia Tryon. 

 Pomatiopsis Hinkleyi n. sp. 



Shell perforate, turrited, decidedly stouter in figure than P. lapid- 

 aria, but less compact and widely conic than P. cincinnatiensis. 

 Olive-brown. Surface with growth-lines about as in P. lapidaria. 

 Whorls 6, very convex, separated by a deep suture. Aperture 



