PART 1 GARTH : PACIFIC OXYRHYNCHA 141 



along its outer margin with one stout blunt subterminal spine and three 

 small spines, one of which is at the anterior angle, and along its inner 

 margin with one or two tubercles. Outer maxillipeds as in O. gracilis. 

 Lower surface pubescent. 



Chelipeds of the female of moderate size, one and a half times as 

 long as carapace, subequal, shaped much as in Oregonia gracilis. Inner 

 surface of merus bordered by short blunt spines. Propodus slightly longer 

 than merus, fingers and palm subequal, margins of palm subparallel, 

 fingers fitting close together, denticulate. Ambulatory legs slender, dimin- 

 ishing gradually in length from the first to the fourth pair, the third pair 

 being the length of the female cheliped. Dactyli contained about one and 

 a third times in the propodi. Chelipeds and ambulatory legs covered with 

 long yellow hair, mixed with shorter and finer hair. (Rathbun, 1904) 



Material examined: None from Allan Hancock expeditions. Through 

 the courtesy of Dr. F. A. Chace, Jr., curator of marine invertebrates, 

 U. S. National Museum, a male and a female specimen from Bowers 

 Bank, Bering Sea, 426 fathoms, June 4, 1906, Albatross station 4771 

 (U.S.N.M. No. 46488), have been made available for the present study. 

 The photographic illustration is of the male. 



Measurements: Male: length 31.8 mm, width 22.7 mm, rostrum 

 4.8 mm, basal width 4.9 mm, cheliped 62 mm, chela 25.6 mm, dactyl 

 11.3 mm, height of palm 7.0 mm, legs 59, 56, 51, and 46 mm, respec- 

 tively. Female: length 29.0 mm, width 20.6 mm, cheliped 37 mm, first 

 walking leg 50 mm. 



Color in life: Unknown. 



Habitat: Bottom types at Albatross stations from which this species 

 was recovered were green mud with Foraminifera, green-brown sand, 

 broken shell, green-brown mud with fine black sand, and gray sand with 

 broken shell. 



Depth: 270-764 fathoms. 



Breeding: Of 44 females obtained by the Albatross at Bowers Bank 

 on June 3-4, 1906, 19 were ovigerous. 



Remarks: Although the range of Oregonia bifurca, Aleutian Islands 

 and Bering Sea, places it almost beyond the scope of this report, its 

 inclusion is justified from the standpoint of pleopod studies, which relate 

 it undeniably to O. gracilis and which prepare the way for a comparative 

 study of Pacific American with the strictly Asiatic members of the genus. 



The bathymetric ranges of the two species might be cited as diag- 

 nostic, since the range of Oregonia bifurca, 270-764 fathoms, and of 

 O. gracilis, shallow water to 212 fathoms, are mutually exclusive. 



