REPORT ON THE AMPHITODA. 121 1 



slightly bent spines, within which is a row of longer spines, straight and strong, and 

 apically denticulate, the series being continued by spines that are much more slender. 



First Gnathopods. — Side-plates small, directed a little forwards, with a spine on the 

 lower margin. First joint reaching much beyond the side-plate, not much longer than 

 the hand, the distal half wide, the front margin nearly straight, the inner surface 

 having a few long setae, each apex carrying some slender spines; the second joint of 

 equal length and breadth, with one or two slender spines at the middle of the hind 

 margin, and a long row round the apex of it; the third joint rather longer, with 

 several groups of spines round the hind margin and across the pointed apex, and one on 

 the convex front margin ; the wrist subequal in length to the hand, but not so broad, 

 broadest at the centre, with spines at the apex of the front margin, the hind margin 

 closelv fringed with numerous spines, the inner surface carrying two oblique rows, one 

 composed of three or four groups passing from the hind margin to the distal ; the hand 

 oval, narrowest at the base, with six groups of spines along the serrate hind margin, 

 the front margin with two or three groups, and the inner surface having seven or eight 

 large groups distributed about it ; the palm gently convex and slightly oblique, joining 

 the hind margin by a gentle curve, a row of about ten palmar spines being set, some 

 on the inner, some on the outer, surface at the junction ; the palm is fringed with 

 submargiual slender spines ; the finger tolerably broad, with smooth inner edge fitting 

 evenly over the smooth edge of the palm, and not projecting beyond it ; a small dorsal 

 cilium near the base ; almost all the spines that have been mentioned, except those of 

 the palm, are finely pectinate. 



Second Gnathopods. — Side-plates deeper than the preceding pair, with the lower 

 margin evenly convex and carrying a spine at the hinder corner. (They are twisted 

 out of their true position in the figure.) The branchial vesicles elongate, widening 

 distally, longer than the first joint. The marsupial plates extensive, far wider and 

 longer than the branchial vesicles, surrounded by setee, not as long as the greatest 

 breadth of the plate. The limb closely resembling that of the first gnathopods, but 

 more elongate, the wrist longer than the hand, and the numerous spines of its hind 

 margin showing in many cases a far stronger pectination. 



First Perasopods. — The side-plates much broader than the preceding pair, broader 

 below than above, with the hind margin concave, a spine on the rounded lower corner. 

 The branchial vesicles a little longer than the first joint. The marsupial plates as in the 

 preceding segment. The first joint reaching much below the side-plate, with the hind 

 margin smoothly convex, carrying a few apical spines, the front margin dilated into a 

 winged lobe near but not at the apex, with two spines at its distal end, the inner margin 

 a little dilated at the upper part, then straight, with an apical group of spines ; the second 

 joint short, with spines at the apex behind ; the third joint much shorter than the fourth, 

 widening distally, with two small groups of spines on the hind margin, stronger spines at 



