498 



CALIFORXIA ACADEMY OF SCIENCES [Proc. 4th Sek. 



Plate III. 



Fig. 1. Nuttallina californica (Nuttall). Exterior view of head valve 

 from Chiton Bed, Point Fermin, California (Lower San Pedro Pleisto- 

 cene) [1026]. 



Fig. 2. Nuttallina californica (Nuttall). Interior view of same valve; 

 same scale as preceding. 



Fig. 3. Nuttallina californica (Nuttall). Profile of same valve; camera 

 outline. 



Fig. 4. Nuttallina californica (Nuttall). Exterior view of median valve 

 from Nob Hill Cut, San Pedro, California (Lower San Pedro Pleistocene) 

 [653] ; same scale as Fig. 1. 



Fig. 5. Nuttallina californica (Nuttall). Interior view of same valve; 

 same scale as preceding. 



Fig. 6. Nuttallina californica (Nuttall). Anterior elevation of same 

 valve ; camera outline. 



Fig. 7. Nuttallina californica (Nuttall). Exterior view of tail valve 

 from Chiton Bed, Point Fermin, California (Lower San Pedro Pleisto- 

 cene) [1028] ; same scale as Fig. 1. 



Fig. 8. Nuttallina californica (Nuttall). Interior view of same valve; 

 same scale as preceding. 



Fig. 9. Nuttallina californica (Nuttall). Profile of same valve; camera 

 outline. 



Fig. 10. Nuttallina californica (Nuttall). Exterior view of median 

 valve of a less mature individual from Deadman Island, San Pedro, Cali- 

 fornia (probably Pleistocene) [678]; camera outline showing shape of 

 uneroded valve. 



Fig. 11. Nuttallina californica (Nuttall). Interior view of same; 

 camera outline ; same scale as preceding. 



Fig. 12. Nuttallina californica (Nuttall). Anterior elevation of same 

 valve ; camera outline ; same scale as preceding. 



Fig. 13. Placiphorella veiata Carpenter. Exterior view of median valve 

 from Deadman Island, San Pedro, California (probably Pleistocene) 

 [677]. 



Fig. 14. Placiphorella veiata Carpenter. Interior view of same valve ; 

 same scale as preceding. 



Fig. 15. Placiphorella veiata Carpenter. Anterior elevation of same 

 valve ; camera outline. 



