122 FRESH-WATER SHELLS. 



spire of rounded whorls, which are separated by deep 

 sutures. Aperture oval; umbilicus small, under the 

 recurved lip; length, one -half an inch. From Wash- 

 ington territory\ 



Limnophysa btilimoides^ Lea, bu-li-moi'-des. The 

 first whorls are small, but the later ones increase 

 rapidly in size, giving the shell a robust appearance. 

 Aperture small, oval ; length, half an inch. From 

 Idaho. 



Limnophysa hitmilis^ Say, hu'-mi-lis, has a small 

 and thin shell, the body -whorl of which is full, while 

 the aperture is half the length of the shell. The 

 latter is only a quarter of an inch long. It comes 

 from southern California. 



Limnophysa catascopiiim^ Say, cat-a-sko'-pi-um. 

 This species is very widely distributed, extending 

 from New England westward. Spire distinct, whorls 

 rounded, body-whorl full, shell very thin, half an 

 inch in length. Specimens from near Oakland, Cal. 

 The variety Adelincr^ Tn'on, from the vicinity of 

 San Francisco, is considered by some as a distinct 

 species. It was named for Miss Adeline Tryon, by 

 her learned brother. 



Fig. no represents a large specimen of Lirnno- 

 physa caperata^ Say, ca-pe-ra'-ta. The spire con- 

 sists of five rounded whorls, the aperture is 

 oval, and the outer lip is slightly reflexed. 

 The shell is horn-colored, and is half an inch 

 or more in length. The specimens before me 

 were collected in Idaho and Utah, but the 

 species ranges over a large part of North 

 Fig. no. America. The variety Binneyi belongs to 

 this species. 



