14 AMNICOLA PORATA. 



tions four, convex, obsoletely wrinkled across; 

 spire obtuse; labrum and labium equally round- 

 ed, meeting above in a subacute angle; the 

 upper edge of the latter appressed to the pre- 

 ceding whirl; umbilicus very distinct." Say. 



COLOR pale ochraceous. 



GEOGRAPHICAL DISTRIBUTION. Inhabits Cayuga 

 lake. Say. 



OBSERVATIONS. 



"Rather larger and more globose than P. 

 limosa, to which it is allied, and has a more dis- 

 tinct umbilicus. It resembles P. dedpiens of 

 Ferussac, but is much less acute, and rather 

 smaller." Say. This shell so much resembles 

 a Valvata, that it is to be regretted that living 

 or operculated individuals have not yet been 

 observed. 



