MUSEUM OF COMPAllATIVE ZOOLOGY. 205 



form of a carina, which becomes obsolete on the hinder part of the gastric 

 region ; this carina is pectinate, or armed with ch)se-set, forward-j)ointing 

 teeth on the anterior part of the gastric region ; the teeth are continued on 

 the upper margin of the rostrum through one third or two fifths of its length, 

 the distal third or three fifths of the rostrum being entirely free trom teeth 

 above ; the lower edge of the rostrum is ciliated above the eyes and armed 

 with three (rarely four) teeth, separated by wide intervals, on the distal half. 



The third abdominal segment is somewhat prolonged posteriorly over the 

 next segment, but the hind margin is rounded off and does not form a promi- 

 nent tooth. The telson is tipped with three pairs of spines, the intermediate 

 pair the longest ; there are, besides, about six pairs of small spines on the dor- 

 sal side of the telson. 



The flagella of both the antennules and antennae are prodigiously developed, 

 the antennule being nearly twice, the antenna more than twice, the length of 

 the whole body including the rostrum ; excepting the proximal part of the 

 organ, the annuli of the antennary flagellum are enlarged at the distal end, 

 giving a beaded appearance to the flagellum. The antennal scale reaches rather 

 more than half-way to the end of the rostrum ; it is truncate at the distal end 

 and armed externally with an apical spine. 



The legs have the characteristic shape and proportions of the genus. The 

 dactyli of the third and fourth pair are slender, acute, somewhat curved, and 

 invested by a pencil of long hairs. The dactyli of the fifth pair are stouter 

 but very short, and hidden in the tuft of hairs which arises from the distal end 

 of the propodus. 



The outer blade of the swimmeret slightly surpasses the telson. It is fringed 

 with long hairs along the internal and distal margin, and furnished with a 

 minute tooth and a movably articulated spine on the external border near the 

 distal end. The inner blade is a trifle shorter than the telson ; it is also fringed 

 along its whole margin with long hairs. 



Dimensions of a female specimen. Length of body, rostrum included, 

 139 mm. ; length of rostrum, 35 mm. ; length of carapace, rostrum included, 

 61 mm. ; kngth of telson, 20 ram. ; length of antennule, 267 mm. ; length of 

 antenna, 315 mm. ; length of antennal scale, 19 mm. 



This species, like all the Nematocarcini, is very fragile. The long and slender 

 rostrum is often broken off during life, and the attempt to restore it sometimes 

 results in an abnormally small and otherwise monstrous rostrum, which might 

 easily be mistaken for a specific character if ample material were not at hand. 



Station 3353. 695 fathoms. 2 specimens. 



