138 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.21 



1894), as well as for additional material obtained on the Harriman 

 Alaska Expedition (Rathbun, 1904) and by various individual collec- 

 tors, see Rathbun (1925, pp. 72-78). 



Atlantic analogue: None. A Pacific boreal species, occurring also in 

 Japan, where Yokoya ( 1933) gives the southern limit on the Pacific side 

 as Inuboe-zaki, 123 m. 



Diagnosis: Rostrum composed of two long, slender, contiguous spines. 

 Postorbital spine remote from eye, acute, directed outward as well as 

 forward. Carapace subtriangular, narrowing at hepatic level. Chelipeds 

 of adult male robust, exceeding walking legs in length, fingers shorter 

 than superior margin of palm. Dactyls of ambulatory legs short and stout. 

 Tip of male first pleopod narrowly acuminate and sharply bent, a row of 

 six long filaments on one side of a line extending basally from the narrow 

 aperture, closed with a seta ; a row of nine filaments on the other side at 

 a higher level, the first five backed by a secondary row. 



Description: Carapace subtriangular, more or less setose and rough- 

 ened by minute prominences. Median, cardiac, and branchial regions 

 tumid. The rostral horns sometimes exceeding the breadth of the inter- 

 orbital space. Postorbital spines slender, acute, inclined forwards, and 

 situated some distance behind the orbit. A prominence on the anterior 

 side of the eye peduncle. The septum separating the antennulary fossettes 

 produced into a spine. Maxillipeds setose, the ischium produced forward 

 into a rounded process at the anterointernal angle. Chelipeds rather 

 slender, the merus subcylindrical and roughened with minute tubercles; 

 carpus rounded ; hand long, slender, somewhat compressed, the margins 

 obtuse; fingers slender, smooth, incurved. Legs subcylindrical and de- 

 creasing in length posteriorly; dactyls slightly exceeding one-half the 

 length of the propodi and terminated by long, corneous claws. (Holmes) 



Material examined: A total of 203 specimens from 23 localities in 

 British Columbia, Washington, Oregon, and California, of which only 

 one was an official Hancock station. (See Table 23) The balance of the 

 material was obtained through cooperating institutions and individuals, 

 notably the Provincial Museum and Dr. J. F. L. Carl, the Friday 

 Harbor Station and Dr. John L. Mohr, the Anacortes Station and Mr. 

 Harold G. Coffin, the California Academy of Sciences, and the Hopkins 

 Marine Station. 



Measurements : Largest specimen, a male: length 60 mm, width 34.6 

 mm, rostrum 18.8 mm, basal width 5.5 mm, cheliped 116 mm, chela 47.5 

 mm, dactyl 20 mm, height of palm 11.6 mm, legs 102, 90, 83, and 75 



