OP CONCHOLOGY. 263 



3. Patula Durantii, Newcomb. 



Plate 4, figure 53. 



Depressed, discoidal, opaque, very minutely striated; spire 

 not at all elevated, perfectly plane above; whorls 4, the last 

 shelving; suture linear; aperture rounded, lunate, ends of lip 

 margin approaching; broadly and perspectively umbilicated. 

 Pale corneous. 



Diam. 5, height If mill. 



Santa Barbara Island, Cal. 



4. Patula Whitneyi, Newcomb. 



Nearly flat above, smooth, suture well impressed ; whorls 4 ; 

 aperture lunate ; with a perspective umbilicus. Smoky horn- 

 color. 



Diam. 5, height 2 J mill. 



Sierra Nevada, Cal. 



5. Patula Cronkheitei, Newcomb. 



Somewhat depressed, a little convex above, ribbed- striate ; 

 whorls 4, suture wide and deep, almost channeled; aperture 

 rounded; umbilicus large, somewhat perspective. Yellowish 

 horn-color. 



Diam. 5, height 3£ mill. 



Klamath Valley, Oregon. 



More elevated and more strongly striate and sutured than 

 striatella, Anth. 



PLANOGYRA, Morse. 

 1. Planogyra asteriscus, Morse. 



Plate 4, figure 55. 



Elevated, planorboid ; whorls 4, very convex ; suture deep ; 

 surface with 25-30 very oblique, thin, raised ribs, between 

 which it is finely striate; umbilicus moderately large, show- 

 ing all the volutions. Light brown. 



Diam 1|, height f mill. 



Maine, Massachusetts. 



Differs from exigua, Stimp., by being smaller, the spire not 

 elevated, and ribs not so numerous. 



