with a revision'of the Limnceidce of Authors. 355 



with a eapnliform .apex, from which concentric undulations ex- 

 tend to the margin. At the short, or posterior extremity, two 

 internal gutters or grooves (one on each side, the right hand one 



the margin ; somewhat resem- 

 iphonaria in appearance. By 

 e is emarginated, especially on 



(S. Rousseau. 



Crimea, with Limncea, Planor- 



IIYSACEA. 



SID^E. Dall. 



al plate (when present) without 

 :th with comb-like, alternating 

 ;entral tooth broad, bifid ; cusp 



y Piiysix^;. 



Drap. 1801. 

 1. Buccal plate chevron-shaped, 

 long. Shell sinistral. 



a. Drap. 1801. 



ovate, outer lip and columella 



rap. 



ella. Ilald. 1842. 

 aperture very wide, with a well- 

 aid. 



'ostatella. Dall. 



ree undulations or costse. 



I'lnjsa costata. Newcomb. 



■;r 



