1916] Weaver: Tertiary Faunal Horizons 45 



of growth; upper surface of body whorl slopes downwards very sharply so as to 

 give the shell an elongate appearance ; base conspicuously produced ; inner lip 

 strongly callused and the callus extending well on to the surface of the body 

 whorl ; outer lip thin and simple ; umbillical opening large ; aperture semi-oval ; 

 many specimens show distinct color banding. 



Dimensions Altitude of shell 30 mm. ; altitude of spire 5 mm. ; maximum 

 diameter 24 mm.; angle of spire 100. 



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 MESALIA GRAY 



MESALIA LINCOLNENSIS n. sp. 

 Plate V, Figure 85 



Description Shell long and narrow with eleven whorls; spire very elevated 

 and whorls convex; on body whorl are usually twelve revolving rounded ribs of 

 moderate development and between these are slightly concave interspaces of dou- 

 ble width ; revolving threads are absent within the interspaces ; there are usually 

 eight similar ribs on each whorl of the spire ; on the extreme upper portion of 

 each whorl for a short distance below the suture the sculpture is less distinct; 

 longitundinal sculpture represented only by faintly developed lines of growth; 

 body whorl obliquely angulated at base and surface below angle is not ornamented; 

 aperture circular; outer lip thin; inner lip slightly callused. 



Dimensions Altitude of shell 2 1 mm. ; altitude of spire 1 4 mm. ; maximum 

 diameter of shell 10 mm.; angle of spire 22. 



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 FICUS BOLTEN 



Ficus WYNOOCHENSIS n. sp. 

 Plate III, Figures 38 and 39 



Description Shell of moderate size; sub-pyriform and evenly rounded; whorls 

 five; body whorl large; spire very low; surface of body whorl ornamented by thir- 

 ty distinct, flat topped revolving ribs; in the interspaces between each of these 



