NEOZOIC INVERTEBRATES 105 



Yoldia breweri sp. nov. 



Pl. IX, fig. 5. 



Shell rather large, short, moderately convex, compressed behind, 

 the posterior end acutely rostrate, short and abruptly recurved ; base 

 roundly arcuate ; anterior dorsal slope convex ; posterior slope deeply 

 concavely excavated ; hinge mostly hidden, teeth small, about three to 

 a millimeter; surface smooth. Length about 25, height 18, length 

 from the beaks to the posterior end 13.5, diameter about 8 mm. 



Locality. Upper beds, 3373. 



Although the impression of the valve is incomplete in front, the 

 form is so remarkable that it seems desirable to apply a name to this 

 species, which has an outline somewhat like Gabb's Meekia navis. 

 It is named in honor of Prof. W. H. Brewer, of Yale University, a 

 member of the Harriman Expedition and formerly of the Geological 

 Survey of California. 



Nucula (Acila) decisa Conrad. 



Pl. IX, fig. 2. 



Nucula decisa CONRAD, Pacific R. R. Reps., vol. v, p. 322, pi. 3, fig. 19, 

 1856. DALL, Trans. Wagner Inst., in, p. 573, pi. XL, figs. I, 3, 1898. 



Nucula divaricata CONRAD, 1848, not of Valenciennes, 1839. 



Nucula conradi MEEK, Checkl. Mio. fos., p. 5, 1864. 



Nucula castrensis GABB, Pal. Cal., II, p. 102, 1868 ; not of Hinds, Voy. 

 Sulph., Zool., p. 61, 1848. 



This species, characteristic of the Eocene of Oregon, is rather 

 common in the upper beds at Chichagof Cove, but the specimens are 

 often greatly distorted by shearing. The one figured, though appa- 

 rently intact, has been elongated to nearly twice its normal length, the 

 form being normally ovate trigonal. The surface is marked with fine 

 divaricate sculpture ; the teeth are strong and sharply folded. 



Glycimeris sp. 



Locality. Upper beds, 3373. 



Shell, when unchanged by pressure, nearly orbicular, plump, con- 

 centrically striated, the inner basal margin entire. Length 21, height 

 22, diameter about 8 mm. The shell can be distinguished from dis- 

 torted specimens of Acila decisa, which sometimes resemble it, by its 

 smooth unfolded teeth. 



Ostrea sp. 



Locality. Upper beds, 3374. 



A crushed specimen of Ostrea resembling O. thirstz Gabb, from 

 the Eocene of Texas was obtained at this locality. 



