1452 THE VOYAGE OF H.M.S. CHALLENGER. 



are by no menus always longer than the third, the reverse being more probably always 

 the case ; the length of the fifth pereeopods, together with their possession of a full 

 complement of joints, makes it inappropriate to speak of them as " presque rudi- 

 mentaires." 



Phorcorrhaphis zamboangae, n. sp. (PL CLXXX.). 



First segment of the perseon longer than the next two united. 



Eyes obscure, probably covering the sides of the head. 



Upper Antennae. — The first joint of the peduncle scarcely longer than broad, perhaps 

 representing the first two joints coalesced ; a short second (or third) joint seems on the 

 under side to be coalesced with the flagellum, of which the first joint is longer than the 

 peduncle, tumid, tapering, the breast seemingly prepared for about fifteen transverse rows 

 of filaments ; on the upper side there is a small slender second joint affixed, which does not 

 reach the apex of the first. The remainder missing. 



Lower Antennae attached below near the back of the head, much smaller than the 

 upper ; third (first free) joint once and a half as long as the fourth ; fourth not broader 

 than long ; fifth about as long as the first, a setule at the lower apex ; these three joints 

 in a continuous line ; the first joint of the flagellum equal in length to the last of the 

 peduncle, half its breadth, bent down at right angles to it ; the second joint minute, 

 blunt, narrower than the first and not half its length. 



Mouth Organs very small and feeble ; the Epistome appears to be shallow and 

 Hat-topped ; of the Mandibles four figures are given, one of part of a mandible in con- 

 nection with the epistome, two of a mandible in connection with the maxillipeds, and one 

 of part of a mandible flattened out and showing the dentate cutting edge, but owing to 

 the minuteness of the objects these figures are all more or less speculative ; if the 

 appearances can be trusted the First Maxillee consist each of a single long plate apically 

 armed with a few straight spines, and the Second Maxillae each of a narrow triangular 

 unarmed plate ; the Maxillipeds are broad, the inner plate broad, distally rounded, and 

 smooth-edged, the outer plates folding partially round its sides and projecting not far 

 beyond it. 



First Gnathopods small and smooth. The first joint with convex margins, narrowest 

 at each extremity, not so long as the four following joints together, the muscles occupying 

 a very small space ; the second joint a little curved, longer than broad, longer than the 

 third joint ; the fourth longer than the second ; the fifth longer than the fourth, with 

 both margins convex, but the front the more so ; the finger more than half the length of 

 the fifth joint. 



Second Gnathopods longer than the first, not inserted close to them, the structure very 

 similar but the first joint narrower ; the third joint as long as the second, the finger as 



