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



the principal plate but on a smaller scale, on the right mandible slighter in its structure, 

 with three slender curved teeth clumped together ; the spine-row not well made out, 

 seemingly of five or six pectinate spines ; the molar tubercle prominent, with the dentate 

 crown not very large, some of the denticles long, the seta small ; a conical process rises 

 near the inner side of the base of the palp ; the palp is fixed over the molar tubercle, the 

 first joint not very short, the second curving outwards at the base and then backwards, 

 the upper part being straight and thinner than the bent basal portion, its front margin 

 boi'dered with spines of various lengths, some ver}^ long, a curved row also taking its 

 origin on the surface from near the base to beyond the centre ; the third joint very slightly 

 curved, shorter and thinner than the second joint, hind margin smooth, front margin 

 slightly serrate, bordered with small spines gradually increasing from the first to the third 

 in each of four sets, with four long spines at the apex, and as many arising along the 

 surface ; on the right mandible this joint in our specimen was longer than on the left. 



Lower Lip broad, not deep ; the front lobes widely dehiscent, the inner lobes little 

 dehiscent, rounded in front, not reaching nearly as far forward, as the principal lobes ; 

 the mandibular processes apically narrowed. 



First Maxilla. — Inner plate widest a little distance from the base, the ciliated border 

 then bending round to the curved apex and carrying two small setae, the longer of which, 

 at some little distance from the other, is plumose and stands near but not on the aj^ex ; 

 the outer plate not large, though longer and broader than the inner, carrying nine slender 

 spines on the broad, scarcely oblique, distal margin, five of the spines having but one lateral 

 tooth, the other four denticulate near the apex ; the second joint of the palp reaching 

 much beyond the outer plate, with sixteen setiform spines extending round the upper 

 part of the inner margin, the apex, and chief part of the outer margin ; an additional row 

 of seven or eight runs on the surface from the middle of the inner margin to the middle 

 of the apex. 



Second Maxillae. — The inner plate broader, very little shorter than the outer, with 

 spines on the apical and upper part of the inner margin, on the latter having also plumose 

 setae ; cilia abundant on both margins ; the outer plate carrying longer spines on the 

 apical margin and some little way down the inner margin, and five short setae spread 

 along the upper half of the hinder border. 



Maxillipeds. — Inner plates small, not reaching the apex of the first joint of the 

 palp, with four setae, not strongly plumose, on the inner margin, the rounded apex 

 set with nine spines besides several slender setae ; the outer plates narrow, reaching 

 beyond the middle of the second joint of the palp, the serrate inner margin being fringed 

 with about thirty spines, the width of which is rather abruptly contracted at some 

 distance from the apex, while the length is irregular, a long one occurring here and there 

 among the shorter, the two near the apex being rather long and curved ; to these 

 succeed three on the apex and three on the hind margin which are setiform ; the first 



