384 CALIFOKNIA ACADEMY OF SCIENCES. 



EXPLANATION OF PLATE XI. 



Fig. I. Pcden ( Plagiodenium) newsomi. sp. iH)V. Upper San Pedro series, Los Cerritos. 



Type specimen, left valve. Altitude 26 mm. ; xi.4- 113 



Fig. \a. Same specimen. Outline, showing convexity of valve. XI.4. 113 



Fig. 2. Pec/en (Chlamys) hericeus Gould. Pliocene, Deadman Island. E.xterior of left 



valve. Altitude 50 mm.; natural size. no 



Fig. 3. Peclen ( Plagioctenha7i) venlt kosus Sowerby. Upper San Pedro series, San Pedro. 



Exterior of left valve. Altitude 36 mm. ; X(.3. 114 



Fig. 3a. Same specimen. Outline, showing convexity of valve; XI.3. 114 



Fig. 4. Pecteii (Chlamys) hastatus SowERBY. Pliocene, Deadman Island. Left valve, 



exterior view. Altitude 38 mm.; X1.3. 109 



Fig. 4a. Same specimen. Outline, showing convexity of valve; X1.3. 109 



Fig. 5. Peclen (Chlamys) hericeus var. stralegus Dall. Lower San Pedro series, Dead- 

 man Island. Exterior of right valve. Altitude 21 mm.; xi.3- no 



Fig. 6. Peclen { Plagioctenmm) vcniricosus Sowekby. Upper San Pedro series, San Pedro. 



Exterior of left valve. Altitude 56 mm.; natural size. 114 



Fig. 6a. Same specimen. Outline, showing convexity of valve; natural size. 114 



