PLATE XXXV. 
Pliocene Pectens. 
(Unless otherwise stated all figures are about two-thirds natural size.) 
Fig. 1. Pecten ( Chlamys) wattsi Arnold. California Acad. Sci. Type. Exterior of 
slightly imperfect left valve; altitude 66 mm. Lower Pliocene, Ivrey- 
enliagen’s ranch, Fresno County. Also found in the lower Pliocene of 
southern California. Right valve with broader, flatter ribs. 
Fig. 2. Pecten ( Pecten) stearnsii Dali. U.S.N.M. 148008. Exterior of left valve; 
altitude 87 mm. San Diego formation (Pliocene), Pacific Beach, San 
Diego County. Not rare in the Pliocene. (See PI. XXXVI, fig. 4, for 
right valve.) 
Fig. 3. Pecten ( Pecten) bellus Conrad. Acad. Nat. Sci. Phila. 960. Exterior of right 
valve; altitude 80 mm.; about five-sixths natural size. Pliocene, Santa 
Barbara. Also found in Pliocene of Ventura, Santa Barbara, and adja¬ 
cent counties. Left valve slightly concave, with narrower ribs than right; 
otherwise similar. 
Fig. 4. Pecten ( Plagioctenium ) circularis Sowerbj-. U.S.N.M. 61246. Right valve; 
longitude 26 mm.; nearly natural size. Pleistocene, Ventura County. 
May also extend down into the Pliocene. 
Fig. 5. Pecten ( Pecten) vogdesi Arnold. California Acad. Sci. Cotype. Exterior of 
slightly imperfect left valve; altitude 74 mm. Pleistocene, Ventura 
County. Also occurs in supposed Pliocene near San Diego. Right valve 
very convex, with broad rounded ribs. 
Fig. 6. Pecten ( Plagioctenium ) cerrosensis Gabb. Univ. California. Exterior of left 
valve (anterior ear slight broken); altitude 106 mm. Pliocene, Cerros 
Island, off Lower California. Also found in the Pliocene near Camulos, 
Newhall, and San Diego. 
Fig. 7. Pecten ( Pecten) auburyi Arnold. California State Mining Bureau. Type. 
Exterior of imperfect right valve; altitude 46 mm. Pliocene, Puente 
Hills, Los Angeles County. Left valve slightly concave, with ribs nar¬ 
rower than in right. 
242 
