ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 187 



the upper San Pedro series at San Pedro. Found also in the Pleistocene at Spanish 

 Bight, San Diego. The specimen figured is from the lower San Pedro series at 

 Deadraan Island, and is now in the collection of Mrs. T. S. Oldroyd. 



Living. — Locality unknown. Reported by Ball. 



Pleisloceiie.- — San Pedro (Oldroyd; Arnold): San Diego (Arnold). 



142. Dentalium semipolitum Broderip <& Soiverby. 



Denia/tion semipo/tfum Brod. & Sby., Cpr., Brit. Assn. Rept., 1863, p. 648. Cooper, 7th Ann. 



Rept. Cal. St, Min., 1888, p. 23S. 

 Dentalium seviistriatiim var. semipolilum Brod. & Sby., Tryon, Man. Conch., Vol. XVII, p. 91, 



PI. XVI, fig. 54, 1898. 



Shell small, thin, tapering posteriorly, curved near posterior extremity; surface ornamented 

 by numerous fine longitudinal ridges; cross-section and aperture circular. 

 Dhnensions. — Long. 10 mm.; diam. 1.4 mm. 



Distinguishable from D. indianorum by striations along the whole length, and 

 smaller, thinner, and more tapering shell. Specimens identified by Dr. Dall. 



Rare in upper San Pedro series at San Pedro, Deadman Island, and Crawfish 

 George's. 



Living. — San Diego to Gulf of California (Cooper). 



Pleistocene.- — San Pedro (Arnold). 



Pliocene. — San Diego well (Dall). 



Genus Cadulus Philippi. 



Shell short, more or less inflated in the middle; apical orifice entire, circular, with annular 

 suboblique internal plica remote from the apex. 



Cadulus subfusiformis Sars is a characteristic species. 

 143. Cadulus nitentior Cmyenter. 



Plate VIII, Fig. 15. 

 Cadulus nitentior Cpr., mss. 



Cadulus fusiforniis Phil., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 231. 

 Cadulus /usi/ortnis Sharp & Pilsbry, Dall, mss. 



Shell small, dingy white or lustrous, tapering, falcate, tubular, thin; surface sculptured by 

 numerous incremental lines, and sometimes by slight constrictions; aperture circular. 

 Dimensions. — Long. 10 mm.; maximum diam. 1.2 mm. 



Common in the lower San Pedro series at Deadman Island and San Pedro 

 bluffs. Found in the Pleistocene at Spanish Bight, San Diego. The specimen 

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

 collection of Delos Arnold. 



Living. — California Coast. 



Pleistocene. — San Pedro; San Diego (Arnold). 



Pliocene, — San Diego well (Cooper). 



