COMPLETE GRAU : PECTINIDAE OF THE EASTERN PACIFIC 69 



ribs fasciculate and imbricate sculpture present when not 

 worn off; disk and ribs solid color or white, infrequently 



mottled rubida (Hinds) 



(Bering Sea to Monterey, California; Japan) 



6. Left valve (and right) with fine lattice-like sculpture over 

 entire disk; ribs not fasciculate and imbricate sculpture 

 weak; ribs of right valve dichotomous only near ventral 

 margin; coloring nearly always mottled to some degree 



rubida jordani (Arnold) 



(Gulf of Alaska to Puget Sound) 



5. Right valve with 9-12 prominent ribs, either broad rounded 

 fasciculi of 5-6 ridges, or narrower dichotomous and not 



fasciculate; color carmine or scarlet 



islandica behringiana (Middendorff ) 



(Bering Sea; Gulf of Alaska to British Columbia) 



5. Right valve (and left) with over 50 low, narrow and pro- 

 fusely imbricated ribs of varying width 



7. Disk occasionally with radial undulations (when present, 

 rather slight) ; hinge line about Yz length of disk; pos- 

 terior auricles of moderate size 



islandica (Miiller) 



(Bering Sea and Aleutian Islands; for complete range see 

 species, this paper) 



7. Disk always with gently rounded undulations, wider on 

 right valve than on left; hinge line about ^2 length of 



disk; posterior auricles very small 



islandica albida (Dall in Arnold) 



(Bering Sea; Aleutian Islands to Japan) 



Ghlamys Islandica (Miiller) 1776 (extra-limital) 



Plate 22 



Pecten islandicus Muller, 1776, p. 248. "I. Horpudiskur . . . Island." 

 —Chemnitz, 1784, p. 314, pi. 65, figs. 615, 616. [Chemnitz' 

 specific names rejected by Internat. Comm. Zool. Nomen., Opinion 

 184, 1944.] 



Ostrea cinnabarina Born, 1780, p. 103. "Patria ignota." 



Pecten islandicus Muller. Fabricius, 1780, p. 415. 



Pecten rubidus Martyn, 1784, pi. 153, fig. 1. "Foudland." [Newfound- 

 land. Martyn's 1784 work rejected by Internat. Comm. Zool. 

 Nomen., Opinion 456, 1957.] 



