44 University of Washington Publications in Geology [Vol. 1 



GENUS CALYPTRAEA LAMARCK 



CALYPTRAEA WASHINGTONENSIS n. sp. 



Plate III, Figure 44 



Description Shell averages medium size for the genus ; nearly circular in 

 outline ; apex very slightly excentric ; spire moderately elevated ; whorls four and 

 one half; shell thin and sculptured by well developed lines of growth; radial 

 sculpture entirely absent; aperture semi-elliptical. This species is much shorter 

 than Calyptraea excentrica (Gabb) and is only very slightly excentric. 



Dimensions Altitude of shell 9 mm. ; altitude of spire 5 mm. ; maximum di- 

 ameter of shell 21 mm.; angle of spire 55. 



Occurrence At locality 256 (University of Washington Palaeontological Col- 

 lection) in railway cuts on the O.-W. R. R. & N. Co. one fourth mile northwest 

 of Lincoln Creek Station in Section 27, Township 15 North, Range 3 West. 



Horizon Lowermost Oligocene; Molopophorous lincolnensis Zone. 



GENUS NATICA SCOPOLI 



NATICA WASHINGTONENSIS n. sp. 



Plate V, Figures 73, 74, 75 and 76 



Description Shell small, high and narrow; whorls four and one-half and 

 sculptured only by moderately developed lines of growth. General outline and 

 shape of shell is similar to Natica lincolnensis but differs from it in that the um- 

 bilical opening is entirely absent. Aperture semi-oval; inner lip heavily callused; 

 the callus extends some distance from the inner lip over on to the surface of the 

 shell. This form is much narrower and elongate than Lunatia oregonensis Conrad. 



Dimensions Altitude of shell 14 mm.; altitude of spire 3 mm.; maximum 

 diameter of shell 11 mm.; angle of spire 60. 



Occurrence At locality 256 (University of Washington Palaeontological Col- 

 lection) in railway cuts on the O.-W. R. R. & N. Co. one fourth mile northwest 

 of Lincoln Creek Station in Section 27, Township 15 North, Range 3 West. 



Horizon Lowermost Oligocene; Molopophorous lincolnensis Zone. 



NATICA LINCOLNENSIS n. sp. 

 Plate V, Figures 71 and 72 



Description Shell very high, elongate-ovate and with five whorls; spire highly 

 elevated but not so much as in the case of Lunatia oregonensis Conrad which it in 

 many respects resembles. Shell smooth except for moderately developed lines 



