52(5 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



Plate XII. 



Fig. 1. Ischnochiton sanctaemonicae Berry, n. sp. Exterior view of 

 head valve from Long Wharf Canyon, Santa Monica, California (Upper 

 San Pedro Pleistocene); paratype [881]. 



Fig. 2. Ischnochiton sanctacmonicae Berry, n. sp. Interior view of 

 same valve ; same scale as preceding. 



Fig. 3. Ischnochiton sanctacmonicae Berry, n. sp. Profile of same 

 valve ; camera outline. 



Fig. 4. Ischnochiton sanctaemonicae Berry, n. sp. Exterior view oi type 

 specimen, a median valve from Long Wharf Canyon, Santa Monica, Cali- 

 fornia (Upper San Pedro Pleistocene) [883] ; same scale as Fig. 1. 



Fig. 5. Ischnochiton sanctacmonicae Berry, n. sp. Interior view of 

 same valve ; same scale as preceding. 



Fig. 6. Ischnochiton sanctacmonicae Berry, n. sp. Anterior elevation 

 of same valve; camera outline. 



Fig. 7. Ischnochiton sanctaemonicae Berry, n. sp. Exterior view of tail 

 valve from Long Wharf Canyon, Santa Monica, California (Upper San 

 Pedro Pleistocene) ; paratype [886] ; same scale as Fig. 1. 



Fig. 8. Ischnochiton sanctaemonicae Berry, n. sp. Interior view of 

 same valve ; same scale as preceding. 



Fig. 9. Ischnochiton sanctaemonicae Berry, n. sp. Profile of same 

 valve ; camera outline. 



Fig. 10. Ischnochiton cf. sinudentatus Carpenter. Exterior view of 

 head valve from Deadman Island, San Pedro, California (probably 

 Pleistocene) [704] ; same scale as Fig. 1. 



Fig. 11. Ischnochiton cf. sinudentatus Carpenter. Interior view of 

 same valve ; same scale as preceding. 



Fig. 12. Ischnochiton cf. sinudentatus Carpenter. Profile of same 

 valve ; camera outline. 



Fig. 13. Ischnochiton cf. sinudentatus Carpenter. Exterior view of 

 median valve from Deadman Island, San Pedro, California (probably 

 Pleistocene) [705] ; same scale as Fig. 1. 



Fig. 14. Ischnochiton cf. sinudentatus Carpenter. Interior view of 

 same valve ; same scale as preceding. 



Fig. 15. Ischnochiton cf. sinudentatus Carpenter. Anterior elevation 

 of same valve; camera outline. 



Fig. 16. Ischnochiton cf. sinudentatus Carpenter. Anterior elevation 

 of another valve from same lot [705] ; camera outline. 



Fig. 17. Ischnochiton cf. sinudentatus Carpenter. Profile of tail valve 

 from Deadman Island, San Pedro, California (probably Pleistocene) [706] ; 

 camera outline. 



