CONCHOLOGIA CESTRICA. 49 



below; pale fuscous, minutely striate ; whorls 4; aper- 

 ture transversely-lunate ; umbilicus wide ; lingual mem- 



P. minutissimum. Jaw of P. minutissimum. 



[B. & B.] [Morse.] 



Fig. 82, Fig, 83, 



brane with 54 arched rows of 13-1-13 teeth, each ; buccal 

 plate consisting of sixteen, corneous lamina, partially 



Lingual- Dentition of P. minutissimum, [Morse.] 



Fig, 84, 



overlapping, and recurved, on their cutting edge. H. 

 i, W. \y 2 , mill. 

 Station, among fallen leaves. Western Pennsylvania. 



Family SUCCINID^E. 



Shell oblique-ovate, imperforate, thin, pellucid, uni- 

 colored ; spire very small ; body whorl large, inflated ; 

 aperture large, oval, or ovate ; peristome simple, acute ; 

 animal resembling that of Helix; tentacles short, conoid. 



OBS. These animals mostly affect low grounds, 

 along the margin of streams, or where it is subject to 

 overflow; while others are found only on high ground, 

 remote from water. When supplied with abundant food, 

 and moisture, they seem almost too large to enter fully 

 into their shells ; when these fail them, and on the 

 approach of cold weather, this difficulty ceases. In 

 organization, they are very much like the common 

 snail, and their general habits are also very similar. 

 5 D 



