448 Mr. G. M. Thomson on two new 



joint elongated and flattened, broadening upwards, with scat- 

 tered setaj along the margins, third joint shorter than second 

 and broadened upwards, with a transverse crest of setaj on the 

 dorsal surface and a fringe of setffi round the extremity and 

 distal half of the lower margin, those at the apex of the joint 

 very long. 



First maxillce with the inner plate in the form of an ex- 

 tremely short pointed lobe without any setae ; outer plate 

 broad, nearly square at the extremity, ending in ten short 

 spines and a few minute setaj ; palp broad and flat, appa- 

 rently three-jointed, the middle joint short, the extremity with 

 a few short spines^ and seta^. 



Second maxillce with the outer plate slightly broader than 

 the inner, setose at ihe extremity; the inner fringed with 

 short seta?, chiefly round the inner margin. 



Maxillrpecls. — Inner plate reaching to the first joint of the 

 palp, widening above and bearing on the extremities a few 

 short broad spines, interspersed with short plumose setae, 

 which are continued a little way down the inner margins; 

 outer plates about subequal with second joint of the palp, 

 half as long again as the inner, broad and curved, furnished 

 with numerous leaf-like spines and long simple setffi ; palp 

 four-jointed, the three last joints furnished with numerous 

 setaj; last joint short and rounded, with one or two rather 

 stout setffi at the extremitv, but without a claw. 



First gnathopods small; side-plates elongated, widening 

 and rounded below, produced forwards at their infero-anterior 

 angle ; basos long and slender, front margin nearly straight, 

 without setai; ischium short; meros produced into an acute 

 tip, sparingly setose ; carpos well developed, subtriangular, 

 broadest at the distal extremity, with several set£e along its 

 sides and numerous tufts on its lower margin; propodos 

 shorter than carpos, narrow-ovate, the oblique and dentate 

 palm occupying about one third of the length, with numerous 

 setfB on both margins ; dactylos about two tliirds as long as 

 propodos, curved, very acute, and furnished with a few minute 

 denticulations along its inner edge. 



Second gnathopods very large, side-plates resembling those 

 of the preceding pair ; ischium and meros short, the latter 

 produced forward like a tile, so that the carpos, which is 

 attached almost at right angles to it, works in it as in a 

 groove ; carpos dilated distal ly, so as to have the form of an 

 equilateral triangle ; propodos large and subquadrate, its 

 lower side straight and fringed witli bunches of short seta?, 

 its anterior side dilated into a large rounded protuberance, 

 furnished with a bunch of seta? near the extremity and a few 



