[68 ] 

 1. Polymita Tryonii, Newcomb. 



Plate (i, figure 3. 



Solid, depressly globose; spire subturbinate, obtuse, suture 

 well impressed ; whorls 6, convex, with numerous minute re- 

 volving lines; aperture rounded, lip scarcely expanded, thick- 

 ened within; columella diagonal, with one or two obsolete 

 tooth-like prominences; umbilicus narrow, covered. Ashy 

 sky-blue above, mottled by streaks of brown, yellowish-white 

 below, an indistinct brown band on the periphery. 



Diam. 25, height 19 mill. 



Santa Barbara and San Nicholas Isles, Cal. 



Var. Superior whorls with white transverse undulating 

 lines. 



2. Polymita intercisa, "Wm. G. Binney. 



Plate 6, figure 4. 



Solid, globose-depressed; spire conic; whorls 5, slightly 

 rounded, closely deeply striate, crossed by deep revolving lines ; 

 aperture obliquely lunar, lip heavy, thickened, dirty white, 

 the extremities connected by a heavy ash-colored callus; um- 

 bilicus covered by the lip, which internally at the base is fur- 

 nished with a tooth like process or elevation! Grrayish-yellow, 

 with an obscure brown band. 



Diam. 22, height 15 mill. 



Oregon. 



3. Polymita areolata, Sowerby. 



Plate 6, figure 5. 



Globose-conic, thin, striate ; spire depressed-conoidal; whorls 

 5, a little convex, the last slightly descending towards the 

 aperture, large, inflated ; aperture rounded lunate, lip thicken- 

 ed within, columellar margin sometimes somewhat dentate, 

 nearly covering the narrow umbilicus; base convex. Cream- 

 color, ornamented with revolving series of interrupted brown 

 lines, light brownish or reddish within. 



Diam. 26, height 18 mill. 



Oregon, California. 



