1016 THE VOYAGE OF H.M.S. CHALLENGER. 



depth of the plate is not equal to its breadth below ; the lower margin serrate. The 

 first joint reaching below the side-plate, with setse on the hind margin, in groups on the 

 inner surface, and at the lower part of the sinuous front margin ; the second joint with 

 an apical group of slender spines behind, and a spine higher up on the hind margin ; the 

 third joint apically pointed in front, slightly serrate, with two groups of spines behind, at 

 the lower hind corner a row of ten small spines, followed by several long ones extending 

 to the front apex ; wrist longer than the hand, nearly as long as the first joint, both front 

 and serrate hind margins and the distal half of the inner surface lined with groups of 

 feathered spines ; the hand oval, at the centre a little wider than the wrist, the front 

 margin, the hind margin and palm, and the surface near the two latter, carrying many 

 groups of more or less feathered spines ; the palm minutely dentate, almost continuous 

 with the serrate hind margin, distinguished from it by the denticulation, by palmar 

 spines, and by the extent of the finger, which fits closely over it ; the palm is also fringed 

 with many submarginal spines and setules. 



Second GnathojJods. — Side-plates not deeper than those of the preceding segment, 

 not much deeper than broad, lower margin serrate, hinder sinuous, with some spines 

 below. Branchial vesicles a broad oval, as long as the side-plate, but not quite so broad. 

 First joint reaching much beyond the side-plate, rather longer than the branchial vesicle, 

 with long setce on both margins ; third joint not much longer than the second, both front 

 and hind margins apically produced to a point ; the wrist triangular, cup-like, length and 

 breadth subequal, the convex serrate hind margin apically pointed, with numerous groups 

 of long and short serrate spines along it, the straight front margin almost unarmed ; the 

 hand oval, wider than the wrist and considerably more than twice its length, with eight 

 groups of spines on the hind margin, aud several small groups near and at the apex of 

 the long front margin ; the palm is oblique, fringed with numerous short spines and 

 setules, and the somewhat massive finger closes over it, laying its tip on the inner 

 surface between two palmar spines, one of which is on the surface, the other on the 

 margin, but the surface spine is accompanied by a curved group of setules placed in a 

 small depression of the inner surface. 



First Perseopods. — Side-plates scarcely differing from the preceding pair, the 

 branchial vesicles rather longer. First joint of the limb more slender than in the 

 preceding pair, with several spines along the hind margin, besides setse of various 

 lengths on both margins ; the third joint much longer than the fourth or fifth, with a 

 few spines and spinules on the margins ; fourth and fifth joints subequal, with spines on 

 the hind margin and spinules on the front, with an apical group of setae ; the finger 

 small, not half the length of the fifth joint, the inner margin raised above the minute 

 nail and there carrying two short setules. 



Second Pcneopods. — The side-plates a little deeper, and branchial vesicles a little 

 longer, than in the preceding pair, otherwise similar ; the limb similar. 



