72 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 23 



Geographical range. Arctic Ocean, except East Siberian and Leptev 

 Seas ; west coast of Norway ; Iceland ; Greenland ; Hudson Bay ; western 

 Atlantic, from Arctic Ocean to Chesapeake Bay; Bering Sea and Aleu- 

 tian Islands. 



Geochronological range: Pliocene, Pleistocene, Recent. 



Bathyynetric range: Low tide to 150 fathoms. 



Ecological data: Usually found on rocky bottoms. 



Chlamys islandica albida (Dall in Arnold) 1906 

 Plate 23, fig. 1 



Pecten (Chlamys) hericius var. albidus Dall (MS, 1904). Arnold, 



1906, p. 136. 

 Pecten (Chlamys) hastatus var. albidus Dall. Arnold, 1906, p. 136, 



pi. 52, figs. 2, 2a. U.S. Fish Commission stations 3311, 3313, 3318 



and 3321, Bering Sea, in 54-85 fathoms. [Type locality station 



3313.] 

 Pecten (Chlamys) crythrocomatus Dall, 1907, p. 170. U.S.S. Albatross 



station 5021 [east coast of Sakhalin Island], in 73 fathoms. 

 Pecten (Chlamys) {hericius Gould, var.?) albidus Dall. Dall, 1921, p. 



18. Aleutian Islands. 

 Pecten (Pecten) hastatus Sowerby variety albidus Dall in Arnold. 



Grant & Gale, 1931, p. 168. Bering Sea. 

 Chlamys (Chlamys) islandica erythrocomata (Dall). Habe, 1951, p. 



73, text-figs. 140, 141. 

 Chlamys (Chla?nys) hastata albida (Arnold). Habe, 1951, p. 73. 

 Chlamys hastata albida (Dall). Kuroda & Habe, 1952, p. 16. Pacific: 



45° N-55° N. 

 Chlamys islandica erythrocomata (Dall). Kuroda & Habe, 1952, p. 



16. Pacific: 51° N?; Japan Sea: 48° N and northward. 

 Pecten (Chlamys) albidus Dall. La Rocque, 1953, p. 31. Aleutian Is- 

 lands. 

 Holotype: U.S. National Museum. 



Type locality: U.S. Fish Commission station 3313, Iliuliuk Harbor, 

 Unalaska, Aleutian Islands, Alaska. 



Original description : Shell of the same shape and general appearance 

 as P. var. hericius, but smaller when adult, being only about 45 milli- 

 meters in altitude. The sculpture on the right valve consists of numer- 

 ous elevated, narrow, thread-like, imbricated riblets, which have the ap- 

 pearance of being grouped together in three or more unequal, equidistant, 

 more or less convex fasciculi ; the interspaces between the fasciculi are 



