ARNOLD] FOSSIL MOLLUSKS FROM CALIFORNIA 447 



ic. Mercenaria perlaminosa Gabb. Cat. No. 165,288, U. S. N. M. Longi- 

 tude of fragment, showing hinge of left valve, 56 mm. Character- 

 istic of this horizon. 



2a. Venericardia yatesi, new species. Cat. No. 165,248, U. S. N. M. 

 Type. Right valve; latitude, 4 mm.; view of exterior, X 6. Char- 

 acteristic of this horizon. 



2b. View of interior of same specimen. 



3. Psephidia barbarensis, new species. Cat. No. 165,238, U. S. N. M. 

 Type. Altitude, 4 mm. ; view of interior, X 4. Characteristic of 

 this horizon. 



4a. Terebratalia hemphilli Dall. Cat. No. 108,495, U. S. N. M. Holo- 

 type. Proc. U. S. Nat. Mus., xxiv, 1902, pi. xl, fig. 10. Ventral 

 valve ; longitude, 35 mm. ; view of exterior, slightly enlarged. 

 Arroyo Burro, west of Santa Barbara. 



4&. Exterior of view of dorsal valve of same specimen. Op. cit., pi. xl, 

 fig. 8. 



