98 LIMN^A. 



14. LIMN^A HAYDENI, Lea. 



Plate 17, fig. 6. 



Shell ovate-conic, smooth, thin, light hom- 

 colored, imperforate ; spire rather short ; 

 whorls five, convex ; sutures deeply impressed ; 

 aperture ovate ; columella strongly plicate. 



Length 25, diam. 12 mill. 



Yellov/stone and Big Sioux Rivers. 



The whorls are more rounded and the shell 

 more cylindrical than L. palustris. 



14. A. LIMN^A SHURTLEFFII, Tryon. 



Plate 17, figs. 7, 8. 



Ovate-cylindrical, rather thin, diaphanous, 

 minutely concentrically striate; spire mode- 

 rately elevated, apex acute, suture impressed ; 

 whorls six, flatly convex, the last one three- 

 fourths the length of the shell, subcylindrical, 

 compressed on the sides ; aperture one-half 

 (72) 



