1482 THE VOYAGE OF H.M.S. CHALLENGER. 



a little longer than the fourth, both rather slender and curved, the fifth shorter than the 

 fourth ; the finger minute. 



Second Perseopods similar to the first, but with the third and fourth joints decidedly 

 longer. 



Third Perzeopods. — The side-plates with a small process on the inner side, forming 

 a blunt triangle. The first joint larger than the branchial vesicles, about as long as the 

 third, fourth and fifth joints together, an oval narrower at the basal than the distal end, 

 and with the front margin flattened, this being a little serrate at the lower end, the whole 

 border fringed with more or less distant setules ; the second joint not reaching the lower 

 margin of the first, the third like the two following, carrying some spinules along the 

 front margin, broader than the fourth, but scarcely so long ; the fourth joint curved, 

 longer than the fifth ; the finger minute. 



Fourth Peraeopods. — Side-plates having on the inner side a process which is a little 

 produced over the first joint in a thin lamina rounded in front, while behind a small 

 hook-like piece connects the process with the side-plate. The first joint large, 

 continuously broad, the front margin concave to fit the convex hind margin of the much 

 smaller first joint of the preceding pair, the hind margin convex from the base for 

 nearly half the length, the remainder straight, the parallel inner edge beginning above 

 the end of the convex part, the lower part fringed with a few setules ; the remaining 

 joints together about half the length of the first, the second not reaching either its 

 hinder or its lower margin ; the third joint longer than the three following together, 

 a little produced at the front apex, its front margin pectinate ; the fourth joint longer 

 and much broader than the fifth, its front margin pectinate ; the fifth joint narrowly 

 oval, with decurrently pectinate front margin, the pectination minute ; the finger curved, 

 minute. 



Fifth Per&opods very small and feeble ; the first joint scarcely longer than that of 

 the first gnathopods but broader, the front margin almost straight, the hinder convex ; 

 the remaining joints minute, together not nearly half the length of the first, their length 

 united scarcely exceeding its breadth, the third joint longer and broader than the fourth, 

 the fourth than the fifth. 



Pleop>ods. — Peduncles stout, produced downwards at the rounded inner angle ; the 

 coupling spines short, the rounded apices forming three or four retroverted teeth ; the 

 cleft spine with a very narrow subapical dilatation of the shorter arm ; the joints of the 

 rami nine or ten in number. 



Uropods. — Peduncles of the first pair about as long as the outer ramus, with some 

 submarginal setules and the lower part of the outer margin pectinate ; the outer ramus 

 shorter and narrower than the inner, both with the margins finely pectinate and the apex 

 very acute ; peduncles of the second pair shorter than the outer ramus ; the rami as in 

 the preceding pair, but respectively shorter, and the outer margin of the outer ramus 



