REPORT ON THE AMPHIPODA. 809 



distally, rather longer than the fourth, with the margins smooth, not as in the preceding 

 pair notched for the spines ; at the apex a group of spines of various lengths, and a small 

 feathered cilium ; no finger apparent. 



Third Perasopods. — Side-plates small, broader than deep, presenting a rounded lobe 

 pointing forwards and upwards, and a more elongate one pointing backwards and down- 

 wards, this latter with its lower margin straight and a spine at the apex. First joint 

 enormously larger than the side-plate, irregularly rounded, broader than deep, the hinder 

 margin smooth, the front one with a few slender spines round the lower half; the second 

 joint small, without spines ; the third very large, equalling the length of the first, and at 

 the centre more than half its breadth, with spines on both margins, but weak ones ; the 

 fourth joint insignificant in comparison with the third, which overlaps it partially behind, 

 but much broader and a little longer than the fifth, with spines on the front margin, and 

 apically behind ; the fifth joint straight, with smooth margins, widening slightly towards 

 the apex about which it carries various spines ; the sixth joint short and stout, not one- 

 third the length of the fifth joint, with a cleanly rounded, in no way pointed apex, instead 

 of a nail carrying three spines of very difi"erent lengths, but similar in structure, each 

 having its distal end bent forward at an obtuse angle, while the hind margin is continued 

 on for a small distance behind the bent part, so that the effect is that of a long Wellington 

 boot, with a delicately-shaped foot ; there is one such spine among those on the fifth joint. 



Fourth Perseopods. — Side-plates similar to those of the preceding pair, but shallower, 

 with two spines on the straight lower hinder margin. Branchial vesicles small, bent 

 directly forwards. The first joint longer than broad, wider above than below, the front 

 margin convex, with spines at three or four points, the hind margin sinuous, the outer 

 surface outdrawn below into a lobe which overlaps the short second joint; the third joint 

 longer than the first, of considerable width, with the sides parallel for most of the length, 

 the spines few and slight ; the fourth joint as long as the fifth and sixth together, which 

 closely resemble those of the preceding pair. 



Fifth Perseopods. — First joint longer than wide, expanding rapidly from a narrow base, 

 widest below ; front margin slightly convex, smooth, hinder slightly serrate ; third joint 

 not longer than broad, much shorter than the first joint and not longer than the fourth, 

 with spines on both margins ; the fourth joint broader but shorter than the fifth, with 

 groups of spines on both margins ; the fifth long, straight, narrowing a little distally, with 

 spines at three points on the front, at two on the hind margin, and a group round the 

 apex, to which in none of the specimens was any finger attached. 



Pleopods. — There are some groups of setae on the peduncles ; the two coupling spines 

 are small, one showing four, the other three, retroverted teeth on one of the margins ; 

 the opposite margin appears to be serrate, but possibly the difi'erence in the aspect of 

 the two margins is due only to the point of view ; the joints of the rami vary in number 

 from seven to eleven ; there is but one cleft spine to each pair. 



(ZOOL. CHALL. EXP. — PART LXVII. — 1887.) XxX 102 



