REPORT ON THE AMPH1PODA. 881 



part of the plate is deeply channelled and below the excavation sends back a long 

 process on the inner side, which interlocks it with the deep channelling of the front of 

 the following segment. First joint of the limb not reaching below the side-plate ; third 

 joint rather longer than the fourth, with spines at four or five points behind, and spinules 

 here and there on the front margin and surface; fourth joint subequal in length to the 

 fifth, armed like the third ; fifth joint with spines at seven points of the hind margin, 

 the spines shorter than on the two preceding joints ; the finger strong, much shorter than 

 the fifth joint, nail sharp. 



Third Perasopods. — The lower apex of the side-plate pointing downwards and 

 backwards, the free front margin continuing the curve of the free hind margin of the 

 preceding plate, the hind margin slightly toothed near the centre. The first joint 

 reaching below the side-plate, a little wider above than below, channelled behind, distally 

 lobed on both edges, the inner lobe crenulate, the front margin carrying several groups 

 of spines and near the top some long setae ; the short second joint distally lobed on both 

 edges behind, carrying some short spines in front ; the remaining joints similar to those 

 of the preceding pair, but longer and stronger. The integument of the limbs and 

 apparently of the whole structure is covered with scale-markings. 



Fourth Perasopods. — The side-plates short and thick, channelled below, on the outer 

 surface a vertical ridge running down to a central apex. The first joint more ex- 

 panded than in the preceding pair, the inner side developing a wing with convex hind 

 margin, crenulate at the lower end ; the following joints as in the preceding pair, except 

 that the third, fourth, and fifth are longer. 



Fifth Perasopods. — Side-plates small, not pointed. First joint of the limb pear- 

 shaped, a little longer than that of the preceding peraeopods and much more expanded 

 behind, except at the distal lobe, which overlaps the short second joint ; the remaining 

 joints as in the two preceding pairs, but shorter than in either. 



Pleopods. — Coupling spines very small, the base broader than the shaft, with six 

 retroverted teeth (including the apical) along one side in succession ; cleft spines eight or 

 nine, with long arms to the cleft, the outer little longer than the inner ; joints of the 

 rami numbering from twenty-four to twenty-seven on the first pair. 



Uropods. — The peduncles of the first pair a little shorter than the subequal rami, 

 which reach as far as or beyond the second, but not so far as the third pair ; peduncles 

 of the second pair shorter than the rami, the outer ramus shorter than the inner ; 

 peduncles of the third pair short, the rami long, broadly lanceolate, subequal, closely 

 overlapping. The marginal spines throughout are small. 



Telson little longer than broad, reaching beyond the peduncles of the third 

 uropods, distally with a triangular emargination, which with the incurving of the lateral 

 margins forms on either side a triangular apex. # 



Length. — The length of the largest specimen, in a straight line from the tip of the 



(ZOOL. CHALL. EXP. PAKT LXVII. 1887.) Xxx 1 1 1 



