36 University of Washington Publications in Geology [Vol. I 



Collection )at bend in Cowlitz River near Vader, Lewis County, Section 28, 

 Township 11 North, Range 2 West. 



VADERENSIS n. sp. var. KINCATDI n. var. 

 Plate X, Figure 17 



Description. Shell large; number of whorls unknown; sides of the whorls 

 straight; suture distinct, linear; surface ornamented with revolving ribs of 

 unequal size; revolving rib on the lower portion of the whorl above the suture 

 prominent and rounded; area below this rib and the suture excavated; between 

 the primary rib and the suture above there are two revolving ribs of secondary 

 size between which are smaller yet distinct revolving ribs ; between the revolving 

 ribs there are microscopic revolving striae ; the ribs have the tendency to become 

 delicately nodose; growth lines fine, very convex, swinging from the suture at 

 an angle of 20 to the middle of the whorl and passing to the suture below at 

 the same angle. 



The revolving ribs and threads of this shell have the same arrangement and 

 gradation in size as that of T: vaderensis n. sp. with the same tendency to become 

 nodose. It differs from that species in a more rounded condition of the lower 

 portion of each whorl, with the large, lower, revolving rib wider and rounded. 

 All the revolving ribs are heavier and less delicately formed. This may be due 

 to an older condition of growth. 



Named in honor of Professor Trevor Kincaid of the Zoology Department, 

 University of Washington. 



Dimensions. Width of median whorl 11 mm. 



Occurrence. At locality 329 (University of Washington Palaeontological 

 Collection) at bend in Cowlitz River near Vader, Lewis County, Section 28, 

 Township 11 North, Range 2 West. 



GENUS ERATOPSIS HOERNES AND AURINGER 1880 



ERATOPSIS CRESCENTENSIS n. sp. 

 Plate XI, Figures 10, 22 



Description. Shell small, ob-ovate; spire concealed; columella region at- 

 tenuated; slight canal; aperture narrow; outer lip thickened, crenulated inter- 

 nally; surface ornamented by spiral ribs which anastomose in the dorsal region; 



