REPORT ON THE AMPHIPODA. 785 



front corner produced to the base of the lower antennae. The first joint reaching 

 beyond the side-plates, distally widening, the front margin smooth, rather sinuous ; 

 the second joint with one pectinate spine low down on the hind margin ; the third joint 

 a little longer than the second, narrowed distally, with three pectinate spines on the 

 apical border, the uppermost the longest ; the wrist triangular, longer than broad, 

 distally somewhat cup-like, the hind margin near the apex having a fringe of eight 

 graduated spines, the lowest and longest less conspicuously pectinate than the others ; 

 the hand much longer than the wrist, the basal part longer than broad, fringed on the 

 hinder side with thirteen finely plumose setae, and on this side carrying a long thumb, 

 tapering to an abruptly curved tip, which is set about with four short curved spines, 

 against which the equally long and almost similarly formed finger antagonizes, making 

 the hand completely chelate ; the thumb and finger are shorter than the basal portion of 

 the hand ; the finger has one or two setules or cilia on the outer margin near the base,, 

 and the thumb has a series along the margin which adjoins the finger. 



Second Gnathopods. — Side-plates with the front margin convex, the width of the 

 plates nearly even throughout. The first joint rather longer than in the preceding pair, 

 not distally widened ; the second joint narrow, as long as the wrist, the hind margin 

 almost straight ; the third joint a narrow oval, much shorter than the second, like it 

 armed only with a cilium near the apex ; the wrist narrowly triangular, longer than 

 that of the first gnathopods, but not so broad distally, with an apical cilium ; the 

 hand similar in general structure to that of the first gnathopods, but longer and 

 narrower, the front and hind margins alike unarmed, except for a cilium on the thumb 

 at some distance from the curved apex, and two spines at the apex ; the border adjoining 

 the finger is armed as in the preceding pair ; the finger, which here as there is narrower 

 than the thumb, has similarly placed cilia. In the Plate the more highly magnified 

 figure of the apex of this limb has been left without the line of dots which should have 

 connected it with the smaller figure. 



First Perseopods. — Side-plates squared, with the front and lower margins convex, 

 separated by a notch or tooth, the hind margin sinuous, rather longer than the front. 

 The branchial vesicles narrowly oval, very small, little more than half the length of the 

 first joint. The marsupial plates rather longer than the branchial vesicles, apically fringed 

 with long broad setae. The first joint reaching beyond the side-plates, with a few 

 spinules at distant intervals on the margins, which are nearly straight ; the second joint 

 short, with an apical spinule behind ; the third joint with two spinules on the straight 

 hind margin, one on the convex front margin at the centre, and another on its decurrent 

 apex ; the fourth joint shorter than the third, with sjiines at three points of the straight 

 hind margin ; the fifth joint longer than the fourth, suliequal to the third, with spines at 

 four points of the hind margin ; the finger more than half the length of the fifth joint, 

 with a small dorsal cilium near the base, the nail short, sharp, slightly curved. 



(ZOOL. CHALL. EXP. PART LXVII. — 1887.) XxX 99 



