458 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



1849. Chiton (Cryptochiton) stelleri Middendorff, Mem. 



Acad. Imp. Sci. St. Petersb., (6), v. 6, p. 101, 157 



(fide Pilsbry). 

 1869. Cryptochiton stelleri Gabb, Paleont. Calif., II, p. 87. 

 1888. Cryptochiton stelleri Cooper, 7th Ann. Rep. Cal. State 



Miner., p. 237 (recorded from Quarternary of San 



Diego, Cal.). 

 1893. Cryptochiton stelleri Pilsbry, Man. Conch., (1), v. 15, 



" p. 48, pi. 6, f. 6; pi. 7, f. 7-13. 

 1895. Cryptochiton c. f. stelleri Ashley, Proc. Cal. Acad. Sci. 



(2), v. 5. p. 327 (recorded from Neocene of Puris- 



sima, Cal.) 

 1897. Cryptochiton stelleri Heath, Proc. Acad. Nat. Sci. Phila.. 



1897, p. 299 (description of young stage). 

 1903. Cryptochiton stelleri Arnold, Mem. Cal. Acad. Sci., v. 3, 

 * pp. 15, 19, 40, 68, 85, 342 (recorded from Pliocene 



and Pleistocene of San Pedro, Cal.). 

 1906. Cryptochiton stelleri Arnold, Pectens of Calif., pp. 31. 35 



(listed from Pliocene and Pleistocene of San Pedro. 



Cal.). 



Diagnosis: Valves large, solid, heavy; visible tegmentum 

 entirely wanting in all later stages of growth ; both anterior 

 and posterior outlines of valves ii-viii bilobate ; jugal sinus very 

 deep; tail valve with a well developed posterior sinus; slits 4 

 to 7, 1-1, 1-1. 



Recorded Range: 



Pliocene: Purisima Formation — Purisima, California 

 (Ashlev). San Diego Formation — Pacific Beach, California 



(!)■ 



Santa Barbara Formation — Deadman Island, San 



Pedro, California (Arnold). 



Pleistocene: Lower San Pedro Series — Deadman Island. 

 San Pedro, California (Arnold) ; Nob Hill Cut, San Pedro. 

 California ( !) ; Chiton Bed, Point Fermin, California ( !). 



Upper San Pedro Series — "Coal mine". West side of 

 Point Loma, California ( !) ; C. A. S. Loc. 108, 2 miles north 

 of Point Loma, California ( !). 



Formation doubtful — San Diego, California (Cooper). 



