86 LIMN^INiE. 



Roman, while others, including the more re- 

 cently described species, are in Italics : 



1. Shell sub-ovate, last whorl ventricose; 

 aperture more than half the length of the 

 shell, greatly expanded. 



Genus Limn^a, Lam. 

 L. ampJa, Mighels, L. decollata, Mighels (= 

 catascopium, pai^s. Hald.), L. columella. Say, 

 L. macrostoma, Say, L. casta, Lea. 



2. Shell spiral, oblong, translucent, horn-col- 

 ored ; spire acute, more or less produced, 

 last whorl ventricose ; aperture large, wide, 

 rounded in front ; inner lip with an oblique 

 fold ; outer lip simple. 



Subgenus Auricula, Klein. 

 L. stagnalis, Linn. (= jugularis and ap- 

 pressa. Say), L. lepida, Gould. 



3. Shell thick in texture, ovate, inflated; 

 spire short, outer lip not expanded. 



Subgenus Bulimnea, Hald. 

 L. megasoma. Say. 



4. Shell ovate-oblong; spire conic; about as 



(60) 



