208 C'ALIFOUNIA ACADKMY OF SCIENCES. 



Tlu' spi'oiincn fijjnrt'd is from tlic lower San Peilro series at Deadman Island, and is 

 now in the collection of Delos Arnold. 



Living. — Santa Barbara Island to San Dictio (Carpenter): Calalina Island, 

 L'O fathoms (Arnold, 1!H)1). 



/'leistocene. — San Pedro (Arnold): San Dioi^o (Sloarns). 



Pliocene. — San Qnentin Bay, Lower California (Orcntt). 



325. Caecum crebricinctum Carpenter. 



Pi.ATK VIII, Via. 10. 



Caciim crebricinchim CvK., Brit. As.sn. Rept., 1863, p. 655; Proc. Cal. Acad. .Sci., Vol. Ill, 1865, 

 p. 215. Tryon. Man. Conch., Vol. VIII, p. 218, PI. LXVII, fig. 71, 18S6. Keep, 

 West Coast Shells, p. 73, 1892. Dall. Trans. Wagner Inst. Sci., Vol. Ill, Part 2, 

 1892, p. 300. Williamson, Proc; U. S. Nat. Mus., Vol. XV, 1892, p. 204. 



Shell small, white, curved, tubular, thin; ornamented with very fine, close, annular ring 

 sculpture; plug subangulate, bent toward conve.x side. 

 Dimensions. — Long. 5.5 mm.; hit. i mm. 



Distinguishable from C. ra/ifornicu)it by its larger size and less prominent 

 rings. The specimen described was identified by Dr. Dall. 



Found in the lower San Pedro series of Deadman Island and San Pedro, and 

 in the upper San Pedro series of San Pedro and Crawfish George's. The specimen 

 figured is from the lower San Pedro series at San Pedro, and is now in the collection 

 of Delos Arnold. 



Living. — Monterey to San Diego (Car])entci) : San Pedro (Williamson): 

 Catalina Island, 20 fathoms (Arnold, 1901). 



Pleistocene. — San Pedro (Arnold): San Diego; Coronado Beach (Dall). 



Pliocene. — San Quentin Bay, Lower California (Orcutt). 



326. Cgecum magnum Stearns. 

 Platk VIII, Fig. 16. 



Cteciim magnuvi Stearns, Tryon, Man Conch., Vol. VIII, p. 219, Pis. LXN'II, LXXXIII, 1886. 



Shell small, tubular, curved, tapering; surface sculptured with numerous fine rings; aperture 

 circular; plug sharp. 



Dimensions. — Long. 5 mm.; latitude, base, 0.9 mm.; ape.x 0.3 mm. 



This species resembles C crebricinctum, I)iit differs from that species in being 

 more curved and in tapering ranch more rapidly from the anterior to the posterior 

 extremity. Specimen identified by Dr. Dall. Tryon's figure may be of C. crehri- 

 cinctuni. One specimen from the lower San Pedro series of Deadman Island, which 

 is figured, and is now in the collection of Delos Arnold. 



Living. — ? 



Pleistocene. — San Pedro (Arnold). 



