REPORT ON THE AMPHIPODA. 887 



carries two spine-teeth at its Inner apex, and a larger one at the centre ; the outer plates 

 broad, reaching just beyond the first joint of the palp ; the inner margin thin and smooth 

 below, above finely pectinate, the pectination passing round part of the apex, and the 

 appearance of it repeated three or four times over in parallel lines on the surface, which 

 carries two rows of longer and shorter setae, neither of them very numerous ; there arc 

 also setae round the outer part of the distal margin ; the first joint of the slender palp is 

 longer than the second, the second a little longer than the third, the finger slight, half 

 the length of the second joint ; the first joint has a spine or two at the inner apex, the 

 second some along the upper part of the inner margin, and the third several along 

 the upper two-thirds of that margin, these spines being pectinate on two edges at 

 the centre. 



First Gnatltopods. — The side-plate takes the form of a triangular process directed 

 forwards, carinate below, channelled above, sharply pointed, with the sides near the 

 point serrate. The limb is long and slender, the first joint being the thickest part ; this 

 is slightly sinuous, very elongate, a little shorter than the wrist and hand united ; it has 

 some minute spinules on the margins and a spine on the hinder apex ; the second joint 

 has the hinder margin straight, much longer than the front, with some small spines at 

 the apex ; the third joint is longer than the second, the front margin very short, the 

 hinder with a row of spines along it near the sharply pointed apex, no part of the very 

 oblique lower margin being free ; the wrist longer than the hand and more than twice as 

 long as the third joint, carries spines all along the free hind margin, pectinate at or 

 near the centre; the hand long and slender, about five times as long as its greatest 

 breadth, which is near the base ; it has a spinule here and there on the hind margin, 

 and at the slightly serrate distal end of it a row of five short spines, each with an 

 accessory thread, and accompanied by one or two setules ; these spines may be con- 

 sidered as occupying the palm margin together with one stronger, curved, closely set 

 within with denticles, at a little distance from the others and close to the finger hinge ; 

 over these spines the small finger closes, having at its centre a strong tooth, with two 

 broad apically hooked setules arising at its base ; beyond the tooth the finger is pro- 

 longed in a slender much-curved nail. 



Second Gnathopods. — The side-plates are similar to those of the preceding segment 

 except that the carina appears above instead of below, and the triangle is a little longer 

 and thinner. The branchial vesicle is about the length of the side-plate, without folds, a 

 somewhat bent oval. The marsupial plates are narrow, longer than the branchiae, with 

 no setas present, but some setules and marks of the points at which setse apparently had 

 been or were to be developed. The limb membranaceous and otherwise similar in 

 structure to the first gnathopods, but much longer ; the first joint a little longer than 

 the third and fourth united ; the third joint with fewer spines than in the preceding pair ; 

 the wrist of great length and tenuity, having scarcely any armature, the hand of about 



