102 



GEOIyOGY OF lyA SALIvE COUNTY. 



its txtremeties nearly joined by a callus on parietal 

 margfin; has four teeth in the aperture, on the margfin 

 of the Hp and within; leno-th 5 mill. Dia. 2>2 mill. 

 Abundant. 



Pupa corticaria, Say. — Shell subcylinrical; apex 

 obtuse; whirls five; suture impressed; aperture small, 

 with white, reflected lip; on parietal wall is one tooth; 

 horn colored, leng-th 2^2 mill. Dia. 1>^ mill. Abun- 

 dant. 



SUBFAMIIyY SUCCmiN^. 



Genus Succinea, Drap. — Subg-enus Succinea, 

 Drap, — The animal resembles Helix, but is shorter. 

 They live on the land near water, and on swamp grass 

 millions may sometimes be found. For instance, in the 

 calumet swamps. In our county around swales. I find 

 S. obliqua, however, in situations somewhat removed 

 from water or damp grounds. On the approach of 

 cold weather the species imitate the habits of the 

 Helix^ The shells, oblong-, three to four whirls- — the 

 last much the larg-est. 



Succinea obliqua, Say. — Shell oblong-, ovate; 

 whirls three, the last very larg-e and expanded; lip 

 acute; straw colored, and moderately thick and firm; 

 leng-th three-fourths of an inch. Abundant. 



Grows to a larg-e size in this county. Is thicker 

 than usual. 



Succinea avara. Say. — Shell thin; whirls three; 

 shell straw colored; length one-fourth of an inch. 

 Abundant in meadows in Deer Park. 



Succinea retusa, Lea. — Shell ovate, oblong-, thin, 

 yellowish; whirls three, aperture dilated and drawn 

 back below, length 14 mill. Abundant. 



This is longer than the species described by Dr. 

 Lea. His description was from a single specimen. 

 My specimen is the mature shell. 



