1040 THE VOYAGE OF H.M.S. CHALLENGER. 



fringed with plumose setse ; the third joint is longer, and strongly fringed with long- 

 densely plumose setae along the whole of both margins, it is slightly less broad at the 

 distal end than higher up ; the hand is rather longer, and the finger not being longer is 

 therefore less in excess of the length of the two preceding joints united. 



Third Perseopods. — The side-plates broad but shallow, the hind lobe less deep than 

 the front, and having the hind margin of the first joint attached to it. The branchial 

 vesicles not very large, bent forwards across the first joint, with the upper edge concave. 

 The marsupial plates narrow and short, with seven long setaa about the distal end. The 

 first joint of very irregular shape, the greatest breadth about equal to the length, the front 

 margin describing a great curve, which ends near the apex of the second joint ; it has 

 several spines at intervals, and long plumose seta? inserted either on the margin or at 

 some distance within it ; the hind margin is short and smooth, almost straight, scarcely 

 reaching the top of the second joint ; the second joint is short, partly covered in front by 

 the lower lobe of the first joint ; it has an apical spine and spinule ; the third joint has 

 the appearance of being reversed, the hind margin being straight, with two small apical 

 spines, the front margin very convex, with some spines of different lengths, the apex a 

 little decurrent but not pointed ; the fourth joint is longer, with parallel sides, the front 

 fringed with spines, the hinder straight and smooth, but its slightly decurrent apex 

 carrying a notable group of spines of very various lengths, some of which have for part 

 of their length three lines of denticles ; besides eight stout spines, there are three slender 

 ones, the terminal part of the longest delicately pectinate ; the fifth joint is rather longer 

 than the fourth but more slender, straight, the longer front margin with its apex produced 

 below the insertion of the finger, and armed with a dozen long spines, most of them 

 partially pectinate ; there is also a long spine at the apex, beside tw T o or three spinules ; 

 the hinder margin, which is straighter than the front, has seven spines, of successively 

 greater length ; the finger is very short, abruptly upturned, with a small dorsal cilium 

 close to the hinge, and on the middle of the back a group of many little denticles. 



Fourth Perseopods. — The side-plates very shallow, not lobed, but deeper in front than 

 behind, where they form a rounded point. The branchial vesicles small, placed as in the 

 preceding segment. The first joint of the limb large, projecting in front above, with 

 feathered setas round the prominent corner, the long margin below this almost straight, 

 having small spines at intervals, its lower lobe overlapping the second joint to its apex ; 

 the hind margin curved above and below, but for the chief part nearly straight and 

 smooth, the lower margin behind standing clear from the next joint ; the next two joints 

 as in the preceding pair ; the fourth joint rather wider distally, the hinder apex similarly 

 armed, the front margin with stronger spines ; the fifth joint is set on, as in the preceding 

 pair, near the front apex of the fourth joint ; it has seven spines, rather stout but not 

 elongate, along the front margin, and some on the apex ; there are three on the hind 

 margin ; the finger is as in the preceding peraaopods. 



