THE NAUTILUS. 17 



broken, and on the surface of the adult shells these fractures give it a 

 rough and uneven appearance. 



Patula strigosa var. parma. 



Shell broadly umbilicated, greatly depressed, of a dark dirty horn 

 color, surface somewhat rough, covered with coarse irregular stride, and 

 microscopic revolving lines ; whorls 5 J or 6, subcarinated through- 

 out, somewhat flattened above, rounded beneath, and striped with two 

 chestnut-colored bands, one above and the other just at the periphery ; 

 spire very little elevated, umbilicus moderately large and deep ; aper- 

 ture ovately round, oblique ; lip simple, subreflected, its terminations 

 approaching and joined by a thin callus. 



Height k inch, breadth 1 inch. 



Habitat near Spokane Falls, Washington. 



Patula strigosa var. hybrida. 



Shell umbilicated, depressed, white, spire horn-color, surface of 

 the shell covered with fine oblique stride, and widely separated re- 

 volving raised lines ; whorls 5, flattened above, rounded beneath, 

 the last falling in front, and striped with two faint chestnut bands, 

 suture well impressed ; umbilicus large, showing nearly all the volu- 

 tions ; aperture nearly circular ; lip simple, thickened, its termina- 

 tions approaching and joined by a thin callus. 



Height f inch, diam. f inch, lesser | inch. 



Habitat near Logan, Utah. 



This is an interesting shell as it is the beginning of the forms of 

 strigosa that finally develope the revolving lines into prominent 

 ribs as seen on the surface of var. Haydenll Gabb. 

 Patula strigosa v;ir. albiila. 



Shell broadly umbilicated, greatly depressed, white, tinged with 

 horn color ; surface covered with fine oblique strije and fine 

 microscopic revolving lines ; whorls 6, convex, the last falling in 

 front ; spire very little elevated, apex obtuse, aperture oblique, nearly 

 round ; lip simple, thickened, subreflected at the columella, its ter- 

 minations approaching, joined by a thin callus. 



Height 'I inch, greatest diam. 1 inch, lesser i inch. 



Habitat near Logan, Utah. 



Patula strigosa var. fragilis. 



Shell umbilicated, elevated or globosely depressed, translucent, thin, 

 fragile, somewhat shining, of a dark horn color, surface covered by 

 fine oblique strire ; whorls 5, convex, the last descending in front, and 



