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. 
1, W. 1%, mill. 
Station, among fallen leaves. Western Pennsylvania. 
Family SUCCINIDA. 
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. 
Opss.— 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 
