REPORT ON THE AMPHIPODA. 791 



than the proximal part of the finger, and has at its base, on the inner side, two cilia or 

 setules, one nearly as long as the nail, the other half as long as the former. 



Triturating Organ. — Twelve or more strong spines are set close together at the bases, 

 the apices being very divergent ; these spines are of unusual breadth, narrowing with 

 abruptness apically, denticulate on the inner margin ; they are surrounded by a forest of 

 slender spines. 



First Gnathopods. — The front margin of the side-plates curved to correspond with 

 the under margin of the head, forming an acute angle with the lower margin, which is 

 produced as far as the base of the lower antennae ; these and the next pair of side-plates, 

 though deeper than broad, have a shallow appearance through being so much bent 

 forwards. The first joint of the limb reaching beyond the side-plate, as long as the 

 wrist and hand united, a little dilated at the upper part behind, at the lower part in front, 

 fringed on both margins with sette more or less plumose ; the second joint short, with an 

 apical group of setae behind; third joint triangular, with a very short free margin in front, 

 the lower half of the somewhat convex hind margin fringed with plumose setae, some passing 

 across the acute apex; the wrist long and narrow, more than twice the length of the hand, 

 slightly narrowing distally, with seven set« along the nearly straight front margin, and an 

 apical group, the hind margin crowded with plumose spines of various lengths, the inner 

 surface carr3dng some nine spines not far from the hind margin, some of these spines being 

 abruptly narrower in the pectinate distal half ; the central part of the distal half of the 

 inner surface and the outer surface near the hinder margin is covered with rows of 

 microscopic spinules, which are continued on the centre of the inner surface of the hand 

 liut not reaching the palm ; the hand widens a little distally ; its front margin has an 

 apical group of long setae, with a similar group a little higher up, followed by one or two 

 isolated setee ; the hind margin is pectinate almost to the palm, near which it has a group 

 of four spines with long accessory threads, the spines themselves graduated in thickness, 

 the first being scarcely more than a seta ; the palm is a little oblique, wavy in outline, 

 fringed with long setae, at its commencement having two edges, between which rises a 

 monster palmar spine, on the sinuous inner side of which are from six to seven stout 

 outstanding denticles, and a still larger decurrent tooth ; the finger is long, reaching 

 beyond the palm, the dorsal cilium near the base of the nail, which is much curved, 

 abruptly narrower, but not much shorter than the proximal part of the finger, and having 

 at its base on the inner side some long cilia or setules ; on the inner surface of the hand 

 there are four spines and two long setae. 



Second Gnathopods. — Side-plates very similar to the preceding pair, but wider above 

 and less sharply produced below. Branchial vesicles elongate, oval, longer than the first 

 joint of the limb. Marsupial plates narrower than the branchial vesicles but rather 

 longer, distally narrowed, fringed on both margins with setae, of which some at least are 

 lightly feathered. The first joint similar to that of the first gnathopods but longer and 



