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 12 to 16 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 g 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 antennule 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. 
