1456 THE VOYAGE OF H.M.S. CHALLENGER. 



third perseopods is complete ; in this, the needle-like fifth joint is more than twice the 

 length of the fourth, fringed along the front margin with thirty or more tolerably 

 distant setules ; the finger is almost straight, about half the breadth of the apical part of 

 the fifth joint, and perhaps not more than a tenth of the length of that joint, and yet 

 from its tenuity having an elongate appearance ; the nail is small, setule-like. 



Fourth Pereeopods shorter than the third. Branchial vesicles more widened below 

 than in the preceding pair, but not on the whole larger. First joint longer than in the 

 preceding pair and more than twice as broad, the convex hind margin sometimes, but 

 not always, having a little indent," the front with five or six small serration-teeth, the 

 gland-cells large ; the second joint scarcely longer than the proximal breadth, with two or 

 three submarginal setules; the third joint expanded for gland-cells, broad except at the 

 point of attachment, much longer than broad, but not so long as the first joint, the front 

 margin with five or six serration-teeth, the hinder apex more produced than the front one, 

 neither of them acute, each with a little pectination of the adjacent distal margin, stronger 

 behind than in front ; the fourth joint subequal in length to the third, only half the 

 breadth, the front margin cut into twenty-three decurrent teeth, the hinder distal margin 

 finely pectinate ; the fifth joint as long as the first, more slender than the fourth, 

 tapering, its front margin cut into numerous decurrent teeth ; the finger minute, curved. 



Fifth Pereeopods slender, longer than the gnathopods, about as long as the first 

 peraeopods ; the first joint slender, longer than the third and fourth together ; the second 

 short, but longer than broad ; the third curved, shorter and not broader than the fourth ; 

 the fourth rather less curved ; the fifth shorter and more curved than the third : the 

 finger minute, curved, much wider at the base than distally. 



Pleopods. — Coupling spines not observed ; the cleft spine with the dilated arm the 

 longer, its dilatation unsymmetrical and followed by a much produced point ; the first 

 joint of the inner ramus has a sinuous apically pointed interlocking process, the pleopods 

 in this and other respects being probably in close agreement with those of Phorcorrhaphis 

 zamboangse ; the inner ramus has six joints, the outer seven. 



Urojyods. — The peduncles of the first pair shorter than the rami ; the outer ramus 

 narrower but only a little shorter than the inner, finely pectinate near the base, and cut 

 into decurrent teeth for the greater part of each margin ; the inner ramus reaching as far 

 as the apex of the outer of the third pair, with most of the outer margin and the distal 

 part of the inner denticulate ; the peduncles of the second pair shorter than those of the 

 first, and shorter than the rami ; the outer ramus shorter and narrower than the inner, 

 with its outer margin almost smooth, the inner denticulate, the inner ramus nearly as long 

 as the outer of the first pair and ornamented like the inner ramus of that pair ; the 

 peduncles of the third pair widening distally, so that the distal margin equals the length, 

 the rami longer than the peduncles, the outer shorter and much narrower than the inner, 

 its outer margin almost smooth, the inner pectinate and denticulate, the broadly lanceolate 



