1546 THE VOYAGE OF H.M.S. CHALLENGER. 



longer than the third or fourth, with the hind margin more strongly denticulate ; 

 finger small. 



Second Perseopods similar to the first, but third, fourth, and fifth joints longer, 

 especially the fifth, and the denticulation of the third and fourth joints less apparent. 



Third Perseopods. — Side-plates with the front lobe almost acute in front, the hinder 

 squared ; a squarely produced process on the inner surface has the lower hinder apex 

 narrowly produced backwards. Branchial vesicles greatly widened above the centre. 

 The first joint oval, not so long as the next four joints together, the front margin with 

 ten or eleven distant shallow serration teeth, distally somewhat squarely produced 

 beyond the convex hinder margin ; the third joint longer and broader than the fourth, 

 with little teeth along much of the front margin ; the fourth also pectinate distally ; the 

 fifth joint longer than the third, almost smooth ; the finger small. 



Fourth Perseopods.- — The first joint longer and broader than in the preceding pair, 

 much wider above than below, very squarely produced in front below the hind margin, 

 the distal margin finely but not uniformly pectinate, the front margin serrate with fifteen 

 little spinule-bearing teeth, the joint longer than all the other joints together ; the 

 third joint decidedly longer than the fourth, and the fifth than the third, all three 

 conspicuously denticulate with unequal teeth, those on the third joint the largest, 

 standing straight out, those on the fifth joint somewhat decurrent ; the finger small, not 

 much curved, pectinate along much of the inner margin, with a larger denticle in the 

 midst of the pectination. 



Fifth Perseopods. — Side-plates nearly square. The first joint much dilated, much 

 smaller than that of the preceding pair, much longer than the rest of the joints together, 

 the united length of which about equals its breadth ; the third joint is much wider than 

 the fourth, longer than the fourth and fifth together, faintly pectinate on part of the 

 front margin ; the fourth joint is a little longer aud much broader than the fifth, with 

 the front margin pectinate ; the little fifth joint is slightly produced in front ; the 

 minute finger has a triangular front division and a slender curved hinder one. 



Pleopods. — Peduncles stout ; in the cleft spine the arm with the subapieal dilatation 

 is the longer ; the joints of the broad rami thirteen or fourteen in number ; the inter- 

 locking process on the first joint of the outer ramus not very elongate, with sinuous 

 lower margin. 



Uropods. — Peduncle of the first pair prismatic, a little longer than the outer ramus, 

 having a small pectinate distal lobe ; the rami are also prismatic the outer with the 

 outer margins smooth the inner closely denticulate ; the longer inner ramus has the inner 

 margin closely and the outer loosely denticulate ; the peduncles of the second pair 

 little shorter than those of the first, which they resemble, but with the inner apex more 

 produced, their length subequal to that of the outer ramus ; the rami broadly lanceolate, 

 the outer with the lower part of the inner margin denticulate ; the inner ramus broader 



