36 RATHBUN 



Surface of body smooth and naked. Rostrum about one and three 

 fourths times as long as the carapace, slightly arched above the eyes, 

 terminal half slightly ascending ; slender, armed with 1 2 to 1 6 teeth above 

 (including 3 or 4 on the carapace), of which all but the one, two, or three 

 most anterior are movable, and 6 to 9 distant immovable teeth below, 

 diminishing in size anteriorly ; tip bifid, upper tooth the smaller. The 

 posterior of the dorsal spines lies between the middle and the anterior 

 third of the carapace ; the anterior is situated at least as far forward as 

 the distal third of the rostrum. 



Antennal spine strong, pterygostomian slender, feeble. Eyes large, 

 pyriform. 



Peduncle of antennulas reaching to the middle of antennal scale ; 

 second and third joints subequal ; outer flagellum twice as long as cara- 

 pace, its basal third thickened ; inner flagellum longer than outer. An- 

 tennal scale seven eighths as long as carapace, the blade obliquely 

 rounded at the end and exceeding the spine. 



Antennal peduncle extending to end of second joint of antennular 

 peduncle ; flagellum longer than the body. Outer maxillipeds reaching 

 to distal fourth or nearly to end of scale. First pair of feet shorter, but 

 overreaching middle of scale. Of the second pair of feet, the right is 

 one and a half or one and two thirds times the length of carapace ; its 

 carpus is divided into 25 to 27 segments: the left is slenderer and one 

 fourth or one third again as long as the right ; its carpus has about 58 

 segments. The third, fourth, and fifth diminish slightly in length in the 

 order named, the third pair overreaching the scale by at least the length 

 of its dactyl. The dactyli are slender, and are contained in the propodi 

 from three to three and a half times. 



The terminal portion of the third segment of the abdomen is com- 

 pressed and carinated ; a sharp spine or lobe pointing backward is situ- 

 ated at the posterior third of the segment; posterior margin produced 

 backward in an acute lobe terminating in a small spine. A similar spine 

 terminates the truncate fourth segment. Sixth segment elongate, about 

 twice as long as fifth; seventh armed with 7 to 10 aculei on each side, 

 and 4 terminal, of which the submedian pair are slenderer and about 

 half as long as the outer pair. 



Dimensions. Ovigerous female, length 13.5 cm., length of carapace 

 and rostrum 64 mm., of rostrum 41 mm. 



Females carrying eggs were taken August 5th and 6th in Bering Sea 

 (stations 3528, 3530). 



Distribution. Circumpolar. Bering Sea and North Pacific southward 

 on the American coast to Columbia River; 29*^ to 350 fathoms. 



