REPORT ON THE AMPHIPODA. 1323 



there is near the front apex a strong tooth-like spine, and several smaller ones elsewhere 

 besides some setiform spines, of which there are very many on the inner surface of both 

 wrist and hand ; the produced part of the wrist has its margins cut into strong teeth, 

 much of the tooth-margins being also pectinately denticulate ; on one gnathopod the 

 margin facing the hand has six teeth and the other margin six, the large apical tooth 

 making the thirteenth ; on the other gnathopod the margin facing the hand has seven 

 teeth, and the other margin four ; the hand is oblong, about twice as long as broad, 

 the front rather thick with two lines of teeth, each comprising from six to eight, not 

 exactly alike in the two gnathopods, but each line in both gnathopods ending with a 

 strongly produced apical tooth ; the hinder margin is cut into seven or eight unequal 

 teeth with partially denticulate margin, and there is a similar tooth on the distal 

 margin ; the surfaces of the hand are armed like those of the wrist ; the finger is rather 

 more than half the full length of the hand, broad at the base, apically curved and acute, 

 reaching, when bent at a right angle to the hand, beyond the apical teeth of the wrist, 

 its inner margin forming a very small spined tooth, much nearer the hinge than the 

 apex, with two or three little spines or denticles between it and the hinge. 



Second Gnathopods in general structure like the first. Side-plate represented by 

 a rather stronger spine-tooth than that of the preceding segment. Branchial vesicles 

 consisting of two subecmal oval lobes united at the base, a little longer than the third 

 joint. Limb about eleven -twentieths of an inch long, the first joint rather longer than 

 the four following together, with one front edge smooth, the other carrying eight strong 

 teeth, which on one of the gnathopods are supplemented by two small ones, the hinder 

 margin having six teeth, one being the produced apex ; the second and third joints nearly 

 as in the first gnathopods, but larger, and the third with the slender spines more 

 numerous ; the wrist and hand similar but much more elongate ; the wrist has the 

 margin facing the hand cut into eleven denticulate teeth, and the hind margin in one 

 gnathopod into ten, in the other into seven, such teeth, in addition to the long apical 

 tooth ; the hand, which is fully three times as long as broad, has the hind margin cut 

 into twelve teeth, and the front margins much as in the first gnathopods, the inner 

 surface with fewer setiform spines ; the finger is longer than in the first gnathopods, 

 but with its inner margin similarly armed. 



First Pereeojoods. — Branchial vesicles about three-twentieths of an inch long, 

 consisting of one very small lobe and a large one of the length mentioned. Limb about 

 an inch and three-tenths in length, the first joint nine-twentieths of an inch long, with 

 nine prominent teeth along the hind margin, and about as many small ones on one edge 

 of the thickened front ; the short second joint has three teeth along the hind margin, of 

 these the apical being the longest ; the third has fifteen larger and smaller teeth on the 

 hind margin ; the fourth which is a little longer has fifteen or sixteen ; the rather longer 

 but much narrower fifth joint has about thirty minute teeth, the margin in the intervals 



