REPORT ON THE AMPHIPODA. 927 



close to the finger-hinge ; there are five groups of spines along the hind margin of the 

 hand, four near that margin on the inner surface, and other groups adjoining the front 

 margin and its apex ; the finger is short to match the palm, its inner edge divided into 

 four decurrent teeth with cilia, the nail long and sharp, accompanied by cilia at the base ; 

 the dorsal cilium small, not far from the base of the linger. 



Second Gnathopods. — Side-plates oblong, deeper than the preceding pair, a little 

 wider below than above. Branchial vesicles a narrow oval, shorter than the side-plate. 

 Marsupial plates broad oval, much larger than the branchiae, longer than the side-plates, 

 with no setas in our specimen, but indications of their places of attachment. The limb 

 in shape and armature resembling the first pair, except that all the joints are longer; 

 the hand longer than the wrist, with an extra group or two of spines, and the finger with 

 an extra tooth on its inner margin. 



First Perseopods. — Side-plates, branchial vesicles, and marsupial plates as on the 

 preceding segment, but rather larger. First joint of the limb reaching beyond the side- 

 plate, broader and a little longer than in the second gnathopods ; the second joint short ; 

 the third more than twice as long as broad, with small spines or setules at three points on 

 each margin, and a group at each apex ; the front apex decurrent, sharp, with a strong 

 spine close to the tip. 



Second Perseopods. — Side-plates very broad, at the greatest breadth broader than 

 deep, the excavation behind wide but not very deep. Branchial vesicles reaching as far 

 as the side-plate, but much less broad. The marsupial plates longer and broader than 

 the branchial vesicles. The first and second joints as in the first perseopods ; the third 

 rather longer than these ; the fourth joint shorter than the third, with groups of spines at 

 three points of the hind margin, of setules at two points of the front margin ; the fifth 

 joint subequal in length to the third or a little longer, with groups of spines at six points 

 of the hind margin, of setules at four points of the front ; the finger strong, slightly 

 curved, the inner margin produced into a short point in advance of the short naU. 



Third Perseopods. — Side-plates broad, the hinder lobe rather deeper than the front. 

 Branchial vesicles about as long as the first joint of the limb. Marsupial plates a narrow 

 oval, reaching a little below the side-plates. First joint broad oval, wider above than 

 below, with spines on the front margin, the hinder serrate with small cilia in the 

 serrations ; the second joint with spines at the front apex, overlapped behind by the 

 lower lobe of the first joint ; the third joint with four groups of spines in front, five 

 behind, those on the decurrent hinder apex being numerous and strong ; fourth joint 

 shorter than the third, like it widest distally, with three groups of spines in front, two 

 behind ; the fifth joint longer than the third, not widening distally, with five groups of 

 spines on the front margin, three on the hinder, and a group of cUia at its apex ; the 

 finger as in the preceding pair. 



Fourth Perseopods. — Side-plates with a lobe rather deeply decurrent behind. Bran- 



