EEPORT ON THE AMPHIPODA. 071 



margin ; the liaiid drawn out into a thumb of the same length as the finger, with which 

 it forms a complete chela ; its front margin gently convex, the hind margin straight till 

 it curves backward at the thumb, which is ciliate on the inner or palm margin with one 

 or two spines at the tip, against which the curved and ciliated tip of the finger closes 

 tightly ; the hand tapers gently from the base, and has a few small groups of cilia ; the 

 finger is quite small, and so also the dorsal cilium near its base. 



Second Gnathopods. — Side-plates of normal size, excavate in front, dilated below, the 

 rounded lower part projecting over the base of the lower antennte. The marsupial plate 

 narrow. The whole of the limb slender, the first joint long, extending beyond the side- 

 plate; the second joint longer than the third or fifth, but shorter than the wrist; the third 

 joint furred behind, with some spines centrally and near the rounded apex; the wrist long 

 and slender, furred, with many groups of spines on the hinder border and the surface, 

 as also very long ones at the apex both behind and in front ; the hand long and 

 slender, somewhat oval, much furred, and beset with fine pectinate spines, some of great 

 length ; the small finger closing down among some very short stumpy spines, the outward 

 sloping palm and inner margin of the finger wearing a pectinate appearance. 



First Pera^ojjods. — Side-plates longer, first joint shorter than in the preceding pair ; 

 third joint much longer than fourth, scarcely decurrent ; artnature insignificant ; fourth 

 joint somewhat shorter than fifth, with thirteen spines on the hinder margin, the first 

 two and last two minute, the others small and short but thick ; fourteen of these stumpy 

 spines fringe the hind margin of the hand, followed by a much larger one at the hinge of 

 the finger; on the convex front margin are five spinules ; the finger is more than half the 

 length of the hand ; in this and other limbs the nail is purplish, suggesting that the 

 animal when alive may have been of that colour or something akin to it. The bluntness 

 of the marginal spines is probably in part due to use. 



Second Per^ojiods. — ^The side-plates very broad, much broader below than at the 

 base, the excavation carried only a short way down ; the limb as in the preceding pair, 

 but the fifth joint a little longer, and with one more marginal spine. 



Third Perieopods. — The side-plates wider than deep, the hinder lobe descending 

 below the front one. The marsupial plate short, expanded to some extent in the lower 

 half, with its front border and apex notched, but without setae present. The branchial 

 vesicles in this and most of the branchial segments massive, the main sac rather placed 

 parallel with the neck than pendant from it ; a small accessory vesicle in one or more 

 of the centre pairs. The first joint of the limb roundly cjuadrangular, the lower part 

 descending behind the second joint with a width nearly equal to the basal portion ; the 

 front margin with small spines, the hinder not deeply serrate ; the third joint very much 

 longer and broader than the fourth, sharply decurrent behind, spined on both edges ; the 

 fourth joint much shorter than the fifth, with three groups of spines in front; the fifth 

 joint not so long as the third, with seven groups of spines along the front, followed by a 



