GEOIyOGY OF IvA SAIvIvE COUNTY. 



101 



it is a variety, undoubtedly. It differs in its size, and 

 is only found in same situations as H. hirsiita. 



SUBGENUS STROBIIvA— MORSE. 



Helix labyrinthica, Say. — Shell conic, elevated, 

 apex blunt; whirls six; aperture lunate, with teeth 

 within; color chestnut; dia. 2^ mill; heig-ht mill; 

 very abundant in the Fox River Valley, and may be 

 known by its elevated conic shape. 



Genus Pupa, Drap. — This g-enus, founded by 

 Draparnaud, to include the minute species of Europe 

 that had been classed with the Helices, and by some 

 is considered superficial. The genus has, however, 

 been adopted as a good one. The shells are so minute 

 as to require much time, patience and skill to find. 

 The species are semi-aquatic, being" found in damp or 

 wet places, near streams and frequently on drift wood 

 in our rivers. 



SUBGENUS PUPIEEA, EEACH. 



Pupa pentodon. Say. — Shell conical, ovate; whirls 

 five, well rounded with deep suture; aperture semi- 

 circular; peristome sharp and expanded; has a callus 

 on the inner margin of the lip, on which are from three 

 to six denticles; on the parietal wall is one prqminent 

 denticle; horn color; length 2/^ mill. Very abundant. 



SUBGENUS TEUCOCHIEA, AEBERS. 



Pupa fallax Say. — Shell fusiform; turrited; whirls 

 six, smooth; suture impressed; aperture lateral, large; 

 lip expanded but not reflected; color brown; length 6 

 mill. Dia. 2/^ mill. Found in considerable numbers 

 in various localities. 



Pupa armifera, Say. — Shell subfusiform, smooth; 

 whirls six; peristome white and reflected; aperture 

 small, oval, with reflected lip, much thickened within, 



