The Mollusca of Eastern Iowa. 63 



P. PERSPECTiVA. — Say. 



Locally rather common under logs and stones, usually in 

 rather high places. 

 P. striatella. — An/ A. 



Very common uuder logs and leaves on creek bottom-lands. 

 It is also very abundant in the Lcess deposits in which also we 

 have found fossil eggs of the species. 



P. STRIGOSA. — G/(i. 



The form which is known as va?'. cooferi occurs as a fossil 

 in the Z.crss, but no recent specimens have been found in the 

 state. 



Subgenus Stenotrema. — Raf. 



S. HiRSUTUM. — Say. 



Quite common under logs etc., mostly in deep woods. 

 S. MONODON. — Rack., 



Common in rather high, especially rocky woods. Also fos- 

 sil in the Lcess. 

 S. LEAH. — Ward. 



Commonly regarded as a variety of the preceding, but 

 quite constant in its characters. It is common in low swamps 

 on the prairies, whereas the preceding form occurs in wooded 

 country. 



Subgenus Triodo-psis. — Raf. 

 T. APPRESSA. — Say. 



Rare. One specimen was found by Mr. H. F. Wickham 

 in Louisa county. It has also been reported from Marshall 

 county. 



Subgenus Mesodon. — Raf. 



M. ALBOLABRIS. Say. 



Not generally distributed. Abundant near Des Moines and 

 reported from Muscatine by Prof. Witter. We have speci- 

 mens from the extreme northern part of the state. 



