COMPLETE GRAU : PECTINIDAE OF THE EASTERN PACIFIC 1 13 



valve being same as posterior auricles. Byssal notch rather deep and 

 having ctenolium of 5 to 8 teeth. Interior usually smooth, but on in- 

 frequent specimens reverse surfaces of interspaces thickened and angu- 

 lated. Colors: orange, pale yellow-brown to deep brown; white zigzag 

 streaks almost always present. 



Remarks : The subspecies differs from the typical by its shorter hinge 

 line, shorter and less acutely pointed auricles, greater obliquity, lower 

 and broader ribs, and either completely smooth or very weakly sculp- 

 tured surfaces of disks. 



Conrad's "Var. A." must be disregarded, for it was based on a speci- 

 men distinguished only by its orange color, a color very commonly found 

 in this subspecies. 



While the subspecies is frequently found attached to clumps of sea- 

 weed, the typical never is. 



Geographical range: Monterey Bay, California, to Cape San Lucas, 

 Lower California, Mexico. 



G eochronological range : Pleistocene, Recent. 



Bathymetric range: Apparently (from available data) never more 

 than a few feet below the surface. 



Ecological data: Usually attached by byssus to seaweed or eel grass, 

 less frequently to pilings, bottoms of boats, calcareous algae or rocks. 



Hancock Expeditions Collecting Stations: 

 SOUTHERN CALIFORNIA: 28 stations. 

 WESTERN LOWER CALIFORNIA, MEXICO: 9 stations. 



Ghlamys (Leptopecten) palmeri (Dall) 1897 



Plate 36 



Pecten palmeri Dall, 1897, p. 85. ". . . near the head of the Gulf of 

 California." 



Pecten (Aequipecten) palmeri Dall. Arnold, 1906, p. 136, pi. 50, figs. 

 2, 2a, 3, 3a. "Near head of Gulf of California (E. Palmer)." 



''Pecten (Aequipecten) palmeri Dall." Grant & Gale, 1931, p. 206. 

 [Listed in synonymy of P. tumbezensis d'Orbigny, citing "Arnold, 

 . . . , p. 136 in part, pi. 50, figs. 2, 2a, only, 1906." Arnold's 

 figures 2 and 2a not P. tumbezensis, representing, as he said, a "co- 

 type" of P. palmeri-^ 



Aequipecten (Leptopecten) palmeri (Dall, 1897). Keen, 1958, p. 70, 

 fig. 128. 

 Holotype: U. S. National Museum. 

 Type locality: Here designated Guaymas, Sonora, Mexico (northern 



Gulf of California). 



