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



Upper Antennw. — First joint short, tumid ; second and third joints very short, the 

 third a little outdrawn above ; flagellum of eleven joints, the first subequal to the 

 remainder united, and longer than the four-jointed secondary flagellum ; on the first 

 joint of the peduncle a spine-like feathered cilium on the central bulge below, longer 

 feathered cilia on its distal border, and on the next joint ; the usual brush on the first 

 joint of the flagellum, this joint being distally drawn out into a little sharp tooth ; 

 calceoli on several of the small joints. 



Lower Antennw. — First three joints short, gland-cone twisted round towards the 

 first joint ; third joint shorter on the inner than the outer side ; fourth and fifth joints 

 furred above, fifth longer and thinner than the fourth ; flagellum of some thirty-eight 

 joints, with small calceoli seemingly only on every alternate joint. 



Mandibles. — Cutting edge as usual convex, with a small projection above, the rounded 

 part below perhaps a little indented behind ; the secondary plate on the left mandible a 

 little curved, bluntly pointed, too broad to be called spine-like, probably in a worn 

 condition ; spine-row seemingly of three small spines ; molar tubercle prominent, the 

 crown rather elongate ; the palp long, set as far forward as the front of the molar 

 tubercle, the second joint but little longer than the third, thirteen spines at the distal 

 part of the second joint, in the third joint one spine at the back close to the base, on the 

 opposite border nearly a third part free, the row of spines consisting of twelve decreasing, 

 followed by six or seven increasing, in length successively towards the apex. 



Loiver Lip as in the next species, Hippomedon geelongi. 



First Maxillae. — Inner plate not very large, with two plumose sette on the rather 

 broad apex, the inner one much smaller than the outer ; outer plate with eleven dentate 

 spines crowded on and about the apical margin, the inner margin furred distally, the 

 spines near to the inner margin slender, with numerous teeth, the outer more stout with 

 few teeth ; the palp over-arching the outer plate, wiih. nine teeth round its apical margin, 

 increasing successively towards the centre, pectinate on their concave outer edges ; one 

 seta projects near the outer apical angle. 



Second Maxilla. — The outer plate longer than the inner, the sloping apical margins 

 of both fringed with rows of pectinate spines ; on the inner plate there are stiff" plumose 

 setfe as well as spines, and a little below the apex a larger and proportionately less stiff" 

 plumose seta on the inner margin. 



Maxillipeds. — The inner plates reach about to the apex of the first joint of the 

 palp, with three teeth followed by two curved ciliated spines on the apical margin, and 

 one tooth on the inner margin just below the apex ; the outer plates reach as far forward 

 as the second joint of the palp or a little further, the ten teeth of the inner and apical 

 margins increasing in size towards the apex, at which the ninth is the longest, though 

 thinner than the eighth, while the tenth is both shorter and thinner than the ninth ; the 

 second joint of the palp is but little longer than the first ; the third joint is much shorter 



