PART 1 GARTH : PACIFIC OXYRHYNCHA 155 



arched margins than in C. opilio. Lateral margin of the carapace deeply 

 scalloped ; this character alone serving to distinguish very young speci- 

 mens (10 mm and under) from the allied species. 



Chelipeds and legs more coarsely and abundantly spinous than in the 

 allied species. 



Male abdomen with sides a little more concave, terminal segment 

 with its free edge more arched, the segment less invaginated in the 

 preceding segment. (Rathbun, 1925, modified) 



Material examined: 31 specimens from 4 localities in British 

 Columbia and Washington (Puget Sound), through the courtesy of the 

 Provincial Museum at Victoria, the University of Washington at 

 Seattle, and the Pacific Biological Station at Nanaimo. (See Table 26) 

 Also Captains Harbor, Unalaska, 9-16 fathoms, 1871, 1874, W. H. 

 Dall, 1 male, 1 female (U.S.N.M. No. 14675). 



Measurements: Male specimen from Vancouver (not largest ex- 

 amined) : length 72.3 mm, width 80.5 mm, rostrum 5.0 mm, width 8.6 

 mm, cheliped 85 mm, chela 46.7 mm, dactyl 32.7 mm, ambulatory legs 

 150, 135, 125, and 85 mm, respectively. Ovigerous female: length 74 

 mm, width 81 mm. 



Color in life: Yellowish, spines and tubercles tipped with red. 



Habitat: Green or gray mud, occasionally with fine sand or broken 

 shell. Burrard and Kingcombe Inlets are fiordlike arms of the sea, where 

 deep water is found close to shore and conditions of quiet prevail, al- 

 though great variation in tidal levels occurs. 



Depth: Shoal water to 259 fathoms. (Rathbun, 1925) 



Size and sex: The largest male noted in the Burrard Inlet catch 

 referred to under Remarks below measured 108 x 118 mm. It is not as 

 large, however, as the 121 x 139 mm male recorded by Rathbun (1925). 



Breeding: Ovigerous females were taken by the Investigator at 

 Vancouver in June and by the Albatross in the Aleutian Islands in the 

 same month. 



Remarks: The writer was fortunate in being able to participate in a 

 demonstration shrimp trawl made by the Investigator of the Pacific 

 Biological Station in the north arm of Burrard Inlet near Vancouver, 

 British Columbia, in June, 1949. The heavily loaded cod end of the 

 net literally exploded aboard, filling the ship's after deck and gun- 

 wales with shrimp, crabs, and bottom-dwelling fishes. By far the largest 

 and most conspicuous forms were the Brachyura: principally Cancer 

 magister and Chionoecetes bairdi, the latter present in two well marked 

 size groups which were taken to be year classes. Large specimens were 



