152 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 21 



Alaska, 30 fathoms, July 3, 1884, Lieut. George M. Stoney, U.S.N., 

 1 ovigerous female, identified by J. E. Benedict (U.S.N.M. No. 14694). 



(Photo) 



Measurements: Male specimen: length 69.3 mm, width 69.3 mm, 

 rostrum 4.4 mm, width 9.8 mm, cheliped 110 mm, chela 52 mm, dactyl 

 30.5 mm, height of palm 14.8 mm, ambulatory legs 160, 155, 135, and 

 100 mm, respectively. Ovigerous female: length 53.8 mm, width 54.5 

 mm. A male measuring 125.5 x 127.5 mm is recorded from Greenland by 

 Rathbun (1925). 



Color in life: Light brick red above, often irridescent, below yel- 

 lowish white; sides of [legs] shining white. (Stimpson, 1907) 



Habitat: Green and black mud ; fine gray sand and shell. 



Depth: 7-85 fathoms; Sea of Japan (Chionoecetes opilio elongatus) 

 to 1,215 fathoms. 



Breeding: The single ovigerous female examined was collected in 

 July off Arctic Alaska. 



Remarks: The references given above, while including all important 

 synonyms, are complete only insofar as the occurrence of the species it- 

 self in the Pacific Ocean and Arctic Alaska is concerned. Numerous 

 records of Chionoecetes opilio in the Canadian Arctic and North 

 Atlantic, and of C. opilio elongatus Rathbun (1924a) in the western 

 Pacific have been omitted in the interest of brevity. 



The description given is that of Stimpson for Chionoecetes 

 behringianus, a synonym of C. opilio, because it alone of the available 

 descriptions was based upon specimens from the geographical area with 

 which the present work deals, namely, the American Pacific. Sidney 

 Smith (1879, p. 41) states that a comparison of three of the original 

 specimens of C. behringianus with specimens from the North Atlantic 

 coast, and with Kroyer's figure and description, proves them to be 

 identical with C. opilio of Greenland, the differences in the proportional 

 lengths of the chelipeds and first pair of ambulatory legs being attributa- 

 ble to age and sex. 



"The specific name phalangium, originally applied to this species, 

 was rejected by Otho Fabricius himself, on the ground, as he expressly 

 states, that he found it preoccupied by Cancer phalangium J. C. Fabricius 

 (Stenorhynchus phalangium M. Edw.). Having been able to consult O. 

 Fabricius's original description of Cancer opilio, I find that it was pub- 

 lished in 1788, which settles the question of priority over C. opilio J. C. 

 Fabricius ( 1793), and establishes the specific name opilio for this species." 

 (Murdoch, 1885, p. 137) 



