COMPLETE GRAU : PECTINIDAE OF THE EASTERN PACIFIC 141 



1. Shell longer than high; ribs of right valve squarish and sharply 

 angled ; interspaces narrower than sericeus ; concentric lamellae 

 on each valve very fine, but only half as numerous as on sericeus 



diegensis Dall 



(Bodega Bay, California, to Cape San Lucas, Lower California, 

 Mexico) 



Pecten sericeus Hinds 1845 

 Plates 50-51 



Pecten sericeus Hinds, 1845, p. 60, pi. 17, figs. 1, la. "Inhab. Bay of 

 Panama. In fifty-three fathoms, on a muddy floor." 



[non] Pecten sericeus Verneuil. Keyserling, 1846, p. 246, pi. 10, fig. 12. 

 "Aus den Permischen Schichten im grauen Mergelkalke an der 

 LTchta des Wymm, und im Kalksteine am Wei bei Dorfe Kischer- 

 ma." [^ Avicula sericea Verneuil in Murchison, Verneuil & 

 Keyserling, 1845, p. 321, pi. 20, fig. 15.] 



\non\ Pecten sericeus Gronwall & Harder, 1907, p. 28. Denmark; 

 Danian, upper Cretaceous. 



Pecten sericeus Hinds. Dall, 1908, p. 400. "U.S.S. Albatross, station 

 3368, near Cocos Island, Gulf of Panama \lapsus calami; Cocos 

 Island, Costa Rica], in 66 fathoms, rocky bottom, temperature 58° 

 .4 F." 



Pecten (Pecten) sericeus Hinds. Hertlein, 1935, p. 303, pi. 18, figs. 14, 

 15; pi. 19, figs. 3, 4. Panama to Mazatlan, Mexico. — Hertlein & 

 Strong, 1946, p. 56. Santa Inez Bay, Gulf of California, to Pan- 

 ama. Also Maria Madre Island, Clarion Island and Cocos Island. 



Pecten (Janira) sericeus Hinds. M. Smith, 1944, p. 52, fig. 692A. 



Pecten sericeus Hinds. Keen, 1958, p. 69, fig. 125. "The southern part 

 of the Gulf of California to Panama, . . ." 

 Holotype : Previously reported at British Museum, but not traceable 



there at present (1958). 



Type locality : Panama Bay. 



Original description : Testa orbicular!, plano-subconvexa, aequiauri- 



culata, velutina, valva sinistra planulata, prope umbonem subconcava, 



fusca, costis viginti-quatuor, lateribus ad angulum planulatis, cum inter- 



stitiis velutinus ; valva dextra subconvexa, pallida, costis consimilibus, 



interdum subgeminis ; auriculis aequalibus, rectis, velutinis, plicis duabus 



obsoletis; intias alba. 



Additional description: Shell nearly orbicular and rather compressed. 



Average adult specimen 70 mm in height and 75 in length; hinge line 



