186 CALIFORNIA ACADEMY OF SCIENCES 



ranch. Ventura; and in the Pliocene at Pacific Beach, and Kuss School, and in the 

 Pleistocene at Twenty-sixth Street, Spanish Bight, and Pacific Beach, San Diego. 



Living.— Santfi Barbara to Mexico; East Indies; China (Cooper). 



Pleistocene. — Santa Barbara to San Diego (Cooper) : San Pedro; San Diego; 

 Ventura (Arnold). 



Pliocene. — San Diego well (Cooper): San Diego (Arnold). 

 140. Dentalium indianorum Carpenter. 



Plate VIII, Fio. 4. 



Dentalhim (J pretiosum Nutt., Sby., var.) hidiationan Cpr., Brit. Assn. Rept. , 1863, p. 648. 

 Dentalium indianorum Cpr., Cooper, 7th Ann. Rept. Cal. St. Min., 1S88, p. 238. 

 Dentalium preliosum var. indianorum Cpr., Tryon, Man. Conch., Vol. XVII, p. 45, PI. XIII, 

 figs. 4, 5, 6, 8, 1898. 



Shell small, curved, tapering posteriorly, heavy; surface with fine incremental rings, and 

 striated posteriorly; cross-section and aperture circular. 

 Dimensions. — Long. 41 mm.; diam. 3 mm. 



Some of the specimens are much more tapering than others. This species 

 is distinguishable from other members of the genus found in this locality by its 

 heavier shell, and by the striations near the posterior end. Specimens identified by 

 Dr. Dall. 



Not uncommon in the lower San Pedro series of San Pedro and Deadman 

 Island; rare in the upper San Pedro series at Crawfish George's. The specimen 

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

 collection of Delos Arnold. 



Living. — Straits of Fuca to Santa Barbara (Cooper). 



Pleistocene. — Santa Barbara (Cooper): San Pedro (Arnold). 



141. Dentalium pseudohexagonum Dall. 



Plate VIII, Fios. 12 and 12a. 



Dentalium pseudohexagojium Dall, mss. 



De7italiu7n 7ieohexai^onum Sharp & Pilsbry., Tryon, Man. Conch., Vol. XVII, p. 19, 1898, PI. XI, 

 figs. 74-86. 



Shell small, curved, tapering posteriorly, rather heavy; surface ornamented with nine promi- 

 nent, rounded, elevated, longitudinal ridges, with concave interspaces; cross-section nine-sided; 

 aperture round. 



Dimensions. — Long. 28 mm.; anterior diam. 2.8 mm.; posterior diam. 1 mm. 



Distinguishable from the other members of the genus by the number of the 

 ridges. The specimen described was dark colored, whether natural or not is not 

 known. Specimen identified by Dr. Dall. 



Rare in the lower San Pedro series at Deadman Island; one fine specimen 

 collected by Mrs. Oldroyd, and one by Delos Arnold; one or two specimens from 



