150 CALIFORNIA ACADEMY OF SCIENCES. 



87. Tapes laciniata Carpenter. 



Plate XIV, Fig. 5. 



Tapes laciniata Cpr., Brit. Assn. Rept., 1863, p. 641; Jour, de Conch., Vol. XII, 1865, p. 136. 

 Keep, West Coast Shells, p. 186, 1892. Williamson, Proc. U. S. Nat. Mus., Vol. 

 XV, 1892, p. 188. 



Shell large, oval, swollen, thick, but brittle; surface net-like, caused by prominent, thick 

 rounded, concentric frills, and numerous rounded, radiating ridges; margin smooth; hinge and 

 interior parts as in T. staminea. 



Dimensions. — Long. 80 mm.; alt. 68 mm.; diam. 56 mm. 



Resembles T. staminea in outline, but is much larger, heavier, and more 

 brittle, and has a much more decided cancellate sculpture. 



Rare in upper San Pedro series at San Pedro, but rather common at Los 

 Cerritos in the same horizon. The specimen figured is from the upper San Pedro 

 series at Los Cerritos, and is now in the collection of Delos Arnold. 



Living. — Monterey to San Diego (Carpenter). 



Pleistocene. — San Pedro (Arnold). 



88. Tapes staminea Conrad 



Plate XIV, Fig. 4. 



Venus slaminea Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 250, PI. XIX, fig. 15, 

 Tapes staminea Con., Carpenter, Brit. Assn. Rept., 1863, p. 641; = V. lamellifcra Con., (Jour. Phil. 

 Acad., Vol. VII, 1837; not of Wilkes' Exped.); =7'. diversum CoN.; =T. lineatum 

 Con.; = Venus rigida Gld. {fide Gabb, Pal. Cal., Vol. II, p. 97, 1869). Cooper, 7th 

 Ann. Rept. Cal. St. Min., 1888, p. 266. Keep, West Coast Shells, p. 185, fig. 158, 

 1892. Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 188. 



Shell of medium size and thickness, suboval, convex; surface sculptured with numerous, crowd- 

 ed, rounded, radiating ridges, and concentric lines, which are most prominent on anterior end; nolunule; 

 margin sometimes crenulated; hinge narrow; ligament narrow, long; three teeth in each valve; 

 posterior two in right valve and middle one in left valve bifid; pallial sinus long, rounded; muscle- 

 impressions not sunken. 



Dime7isions. — Long. 50 mm.; alt. 42.5 mm.; diam. 30 mm. 



This is a variable species, the shape of the shell and the sculpture varying in 

 different individuals. The form above described is the most common in the San 

 Pedro beds. Specimens identified by Dr. Dall. 



Rare in the lower San Pedro series at Deadman Island and San Pedro; 

 common in the upper San Pedro series at Deadman Island, San Pedro, Los Cerritos, 

 Crawfi-sh George's and Long Beach. The specimen figured is from the upper San 

 Pedro series of San Pedro and is now in the collection of Delos Arnold. Found in 

 the Pliocene at Pacific Beach and Russ School; and in the Pleistocene at Twenty- 

 sixth Street and Spanish Bight, San Diego. 



Living. — Straits of Fuca to Lower California (Cooper). 



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

 (Arnold). 



