1916] Weaver: Tertiary Faunal Horizons 37 



most equilateral showing faint crenulations near the beaks but none on margins 

 of shell. Beaks are strongly recurved. 



This species was named and figured but through error the description was 

 omitted in a report previously published. 3 



Dimensions Altitude 1 3 mm. ; longitude 1 8 mm. ; thickness 9 mm. 



Occurrence At locality 256 (University of Washington Paleontological 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. 



CRENELLA WASHINGTONENSIS n. sp. 

 Plate III, Figure 40 



Description Shell minute, delicate, ovate in outline and tumid. The beaks 

 are almost central and curved anteriorly ; margins of shell finely crenulated. These 

 crenulations extend up to and beneath the beak. They are so prominent along 

 the anterior and posterior margins just away from the beaks that they appear 

 as broad V-shaped teeth. Immediately beneath the beaks there are four vertical 

 ridges and intervening grooves which appear to be extensions of the crenulations. 

 Surface of shell sculptured by 60 minute rounded ribs with narrow grooved inter- 

 spaces about one-third as wide as the ribs. These are crossed by concentric lines 

 of growth. Shell material is thin and has pearly luster on inner surface. 



Description Altitude 3 mm,; longitude 2 mm.; thickness 2 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 PANDORA BRUG 



PANDORA WASHINGTONENSIS n. sp. 



Plate II, Figures 19 and 20 



Description Shell small; right valve moderately convex and left valve slight- 

 ly concave. On left valve anterior dorsal margin deeply concave; anterior end 

 sharply rounded and somewhat flexuous as it passes into the ventral margin which 

 is broadly arcuate; posterior dorsal margin very slightly concave just behind beaks 

 but from that point to posterior end it is straight; posterior end sub-truncate and 



sWeaver, C. E., "A Preliminary Report on the Tertiary Palaeontology of Western 

 Washington," Bull. 15, Wash. Geol. Surv., pp. 94, 1912. 



