REPORT ON THE AMPHIPODA. 1167 



almost oval, a little longer than the fourth, the convex front margin having a very- 

 slender spine and spinule at the apex, the less convex hind margin having two slender 

 spines ; the finger very short at the base, as broad as long, but abruptly narrowing before 

 reaching the sharp upturned nail, with a hair in the cavity ; there is a sharp dorsal 

 tooth preceding the base of the nail. 



Fourth Perasopods. — The side-plates broad and comparatively deep, except at the 

 extremities, the lower margin strongly ciliated. The branchial vesicles, if rightly observed, 

 very small and narrow, bent at the base. The first joint attached near the end of the side- 

 plate, oval, but with the front margin flattened ; this has nine setules in a series, the hind 

 margin has six more scattered ; the second joint short ; the third longer than the fourth, 

 with three setules on the slightly convex front margin and one at the apex of the straight 

 hind margin ; the fourth joint not much longer than distally broad, with a spinule or 

 two at the apex of the convex front, and a long thin spine at that of the straight hind 

 margin ; the fifth joint subequal in length to the third, with a group of slender spines on 

 the apex of the convex front, and two on the lower part of the straight hind margin, 

 which has also a little short apical spine ; the finger as in the preceding pair. 



Fifth Perseopods. — The side-plates much smaller than in the preceding pair, with 

 the lower margin smooth and nearly straight. The first joint a little longer and 

 more pyriform than in the fourth pereeopods ; the third a good deal longer, widening a 

 little distally, the margins nearly straight, both with long apical spines, the front also 

 with spinules at three points; the fourth joint also widening distally, much longer than 

 broad, with the front margin a little convex, and a group of long spines at each apex ; the 

 fifth joint shorter than the third, very little longer than the fourth, with a group of several 

 long slender spines at the apex of the convex front margin, which has two groups higher 

 up, the almost straight hind margin and the finger much as in the preceding pair. 



Pleopods. — On the peduncles of the first pair there appear to be four very small 

 coupling spines, each with an apical pair of hooks, but on the second pair only two spines 

 were perceived ; no cleft spines were discovered ; in the first pair each ramus has nine' 

 joints, the first of the outer ramus much expanded and fringed on the outer side with 

 more then twenty plumose setae ; in the second and much shorter pair, the outer ramus 

 has four joints, the first expanded, with a dozen setae on the outer margin ; the inner 

 ramus has but one joint, shorter and much narrower than the first of the outer ramus ; 

 the third pair is much shorter than the second, the outer ramus two-jointed, the first 

 joint expanded, with eleven setae on the outer margin ; the inner ramus rudimentary or 

 (?) absent. 



Uropods. — The peduncles of the first pair a little longer than the outer ramus, which 

 has the outer margin fringed with little denticles and also with about a dozen setules, the 

 apex finely pectinate, carrying a large spine ; the inner ramus shorter and narrower, with 

 a similar apex, the margins smooth ; the second pair with the peduncles much longer 



