1514 THE VOYAGE OF H.M.S. CHALLENGER. 



Lower Antenna}. — First free joint a little bent at the base, a little longer than the 

 second ; the second scarcely longer than the third ; the third and fourth subequal, all of 

 them smooth, not much angled in position ; there is a minute apical joint. The antennae 

 in the specimen are no doubt those of a young male, the first three joints belonging to 

 the peduncle, and the last two to the flagellum. 



Mandibles. — The cutting edge finely denticulate between the two more prominent 

 teeth, of which one stands at each corner ; the tooth-like process representing the 

 secondary process on the right mandible very small ; the palp (in the specimen) short 

 and curved, with only an indication of division into three joints. 



First Maxillie.— -There are four strong teeth projecting from the distal part of the 

 plate's inner margin, the appearance being suggestive of a little spine-tooth embedded in 

 a process rather wider than the tooth. 



Second Maxillie much shorter than the first, smooth. 



Maxillipeds. — The inner plate nearly as broad as long, the distal margin furred, 

 having at the centre two little embedded spines, the outer corners rounded, the outer 

 plates broad, much longer than the inner, submarginally furred on the inner surface 

 near the inner edge. 



First Gnathopods. — First joint not twisted, dilated at and below the middle, the 

 margins smooth, the front sinuous ; the second joint not longer than broad ; the third 

 longer and broader than the wrist, with narrow neck, distally widened, with a rounded 

 apex in front very slightly produced, the hind margin very minutely pectinate, distally 

 produced into a broad rounded lobe ; the wrist scarcely so long as broad, the front 

 margin convex and apically a little acute, the hind margin sinuous at the narrow neck, 

 then convex and pectinate, projecting far behind the much narrower hand ; the hand 

 longer than the wrist, narrow at the neck and still more at the apex, the hind margin 

 pectinate at the centre; the finger slender, curved, half the length of the hand or a 

 little more. 



Second Gnathopods. — First joint a little longer and less dilated than in the 

 preceding pair ; second joint short ; third joint as in the first pair, but the front and 

 hind apical lobes more equal ; the wrist broader than the third joint, its proximal part 

 shorter than the hand, the broad triangular apical process also shorter than the hand, 

 pectinate on both margins, at the base standing a little apart from the hand, which 

 resembles that of the first gnathopods, but has the hind margin more strongly pectinate ; 

 finger as in the first pair. 



First Perseopods with smooth margins or scarcely perceptible armature. First joint 

 a little bent at the base, and below this the front margin sinuous, the hinder gently 

 convex ; the second joint a little longer than broad ; the third shorter than the fourth, 

 but broader, with narrow neck, the apices rounded ; the fourth narrowing distally, with 

 straight distal margin ; the fifth joint longer than the fourth, slightly bent, narrow, 



