40 University of Washington Publications in Geology [Vol. 1 



investigations have made known the general character of the Tertiary faunas of 

 the Pacific Northwest. 



Dimensions Altitude 64 mm.; longitude 77 mm.; thickness 38 mm. 



Occurrence At locality 241 (University of Washington Palaeontological Col- 

 lection) on Stillwater Creek about one mile above junction of Olequah and Still- 

 water creeks in Section 25, Township 1 1 North, Range 3 West. 



Horizon Upper Eocene; Tejon formation. 



GENUS CARDIUM LINNEUS 



CARDIUM LINCOLNENSIS n. sp. 

 Plate III, Figures 36 and 37 



Description Shell small, sub-quadrate in outline, moderately inflated, rather 

 thin and nearly equilateral; beaks small; surface of shell sculptured by 29 radiat- 

 ing V-shaped ribs and very narrow interspaces, each of which contains a small 

 thread like rib. Concentric striations are very faintly developed. The anterior 

 and posterior ribs are set with small flat nodes; middle portion of shell is almost 

 smooth. Margin serrated and internal surface fluted half way to the umbonal 

 cavity. Teeth well developed and cardinals set one above the other. 



Dimensions Altitude 9 mm.; longitude 11 mm.; thickness 8 mm. 



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 CALLOCALLISTA A. ADAMS 



CALLOCALLISTA ARNOLDI n. sp. 



Plate II, Figure 13 



Description Shell of medium size, thin and sub-quadrate in outline, beaks 

 slightly elevated, strongly curved forwards and situated from the anterior end a 

 distance of about one-fifth the length of the shell. Posterior dorsal margin nearly 

 straight and slowing down from beak at an angle of about 50 and passing into a 

 very broadly rounded posterior margin; anterior dorsal margin slightly convex 

 and sloping downward at an angle of 30; anterior margin very slightly truncate 

 to evenly rounded and passing into a broadly arcuate base. Lunule and escutcheon 

 obscure. Surface sculptured by evenly developed concentric lines of growth; ra- 

 diating ribs are absent. Hinge plate moderately heavy; in left valve there is 



