522 PROCEEDINGS OF THE NATIONAL MUSEVM. vol. xxxv. 



on the first basal joint; the expanded penultimate joint of the pe- 

 duncle armed with nine spines and about ten plumose setae around the 

 lower anterior angle; distal part of lower margin of last basal joint 

 with about eight long plumose setae and a pair of long spines; flagel- 

 lum with about nine joints. Mandibular palp very narrow, the last 

 joint a little longer than the preceding and furnished with setae on 

 its oblique tip and distal half. First maxilla? with the small inner 

 plate rounded and furnished with a large and a small seta; the joint 

 between the first and second segments of the palp not so clearly 

 marked as usual. Maxillipeds with the outer plate reaching about 

 to the middle of the second joint of the palp; last joint of palp very 

 small, furnished with a long curved spine at the tip and two smaller 

 ones on the inner and a short seta on the outer margin. 



First and second gnathopods of nearly the same size and shape ; 

 lower margin of coxa of first pair with over twenty-five plumose 

 setae, those of the three following appendages with fifteen to seven- 

 teen setse. Penultimate pera*opods long, basal joint with plumose 

 setse along the whole of both margins, the hind margin with a convex- 

 ity near the base which is not so prominent as in II. affinis; terminal 

 joint styliform, nearly straight and about half as long as the pre- 

 ceding. Last perseopods very small, the basal joint with about twen- 

 ty-five serrations on the posterior, lower, and a part of the anterior 

 margin ; from each notch between the serrations arises a long plu- 

 mose seta ; ischium with three spines and four plumose seta 1 on promi- 

 nent distal margin; merus with about seven spines on distal portion 

 of anterior margin, many of them accompanied by long sparingly 

 plumose setse; carpus with three pairs of setse on anterior margin; 

 dactyl very slender and about as long as the propodus. 



Third abdominal segment produced at the infero-posterior angle 

 into an acute lobe, which is not strongly upturned ; lower margin 

 with about twenty-two plumose setae ; margin above posterior angle 

 ciliated and furnished with a few slender spines. Fourth abdominal 

 segment gently concave above w T ith no prominent elevation. Outer 

 ramus of third uropods about twice as long as the peduncle, armed 

 with about eight spines on outer margin; terminal segment very 

 small, scarcely longer than broad and bearing a pair of long spines; 

 inner ramus about three-fifths the length of the outer, narrowing 

 distally from an expanded base, and armed with four spines; the 

 distal margin of the peduncle is armed with about ten spines; apices 

 of telson divergent and broadly rounded. 



Length. — 8 mm. 



Locality. — Single female specimen from Station 4342, off South 

 Coronado Island, 53-66 fathoms. 



Type.— Cat. No. 38548 U.S.N.M. 



