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



than tlie fourth, armed like it ; the flagellum broken, a small calceolus on the single 

 remaining, somewhat elongated joint. 



Upper Lip with a broad apical margin. 



Mandibles powerful. The cutting plate at one end has three teeth, of which one 

 is produced considerably beyond the other two ; a flat oblique border leads from these 

 to a small tooth at the other end ; within the main plate in the left mandible is 

 placed a secondary plate of similar shape, with its lower edge cut into five consecutive 

 teeth, of which the outermost is produced much beyond the others ; in the right 

 mandible the secondary plate is much slighter and narrower, apically divided into two 

 denticulate teeth ; the spine-row consists of six or seven denticulate spines ; the very 

 prominent molar tubercle has its crown set with many rows of denticles ; the seta at the 

 upper corner is small ; the long palp is inserted over the molar tubercle. The first joint 

 short, the second long, narrowing distally, with some six groups of spines along its 

 course ; the slender third joint is almost as long as the second, fringed along almost all 

 the inner edge with spines, and having three, of which two are very long, at the apex ; 

 near the l^ase close to the hind margin are two, a long and a shorter one ; all these 

 spines being pectinate on two edges in the lower part. 



Lower Lip. — The principal lobes rounded, very broad ; the mandibular processes 

 rather short, narrow at the apex. 



First Maxillw. — Inner plate very broad, the convex inner margin ciliated, the straight 

 margin which follows at right angles with the convex part carrying five subequal plumose 

 set« at intervals ; the outer plate narrower than the inner, the apical margin not very 

 oblique, armed with nine long spines, four of which are strongly denticulate, the others 

 at the apices strongly furcate ; the palp reaching considerably beyond the outer plate, its 

 first joint short, with some small seta3 on the outer margin, the second long, having slender 

 spines on the apex and upper part of inner margin, nine or ten in number, and half a 

 dozen spaced along the serrate outer margin, and a row on the surface above near the 

 inner margin. 



Second Maxillw. — The plates short and broad ; the inner broader than the outer and 

 reaching as far forward, its inner margin fringed witli cilia, plumose setae, and spines of 

 various lengths, the fringe of spines passing but a little way round the broad apical 

 border, which is not reached by the row of plumose setae which passes inwards along the 

 surface ; the outer plate is fringed with spines round the upper part of its inner margin 

 and the apical border, small spines passing down the upper part of the outer margin. 



Maxillipeds. — The inner plates short, not nearly reaching the apex of the first joint of 

 the palp, with slender teeth and curved spines on the flat-topped apex ; the outer plates 

 not broad, reaching halfway along the second joint of the palp, the inner margin concave, 

 crowded with spines, the longest of which at the beginning of the apical border is followed 

 by five plumose setae ; the first joint of the palp is less than half the length of the second ; 



