14 The American Naturalist. [January, 



Section Microphysa Albers. 

 M. pygmea Drap. 



damp leave-, but it requires close search to find it. 

 Section Helicodiscus Morse. 



H. Imeatas Say. 



Under old logs, in limited quantity. 



Section Strobiln Morse. 



Very common in wet plae,<. 

 S. monodon Hack. Var frnhrrnu. 



Common in woods. 



Section Triodopsis 

 T. palliata Say. 



Rather common on heavy soils. A 

 about Kent. Its habitat is about deca 

 T. injiecta Say. 



Very rare in this county. More 

 found two miles west of Akron a shell 

 size like the new species T. rraigi,,', 

 leads to the suspicion that craigini m; 

 umbilicated variety of this species. 

 T. tridentata Sav. 



18 mm. or more. 

 T.fallaxSay. 

 Much like the above 



