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



smaller teeth ; adjoining the secondary plate is a broad, backward curving spine, of two- 

 thirds the length of the secondary plate, with its broad end divided into sharp teeth of 

 different lengths ; to this succeeds a much shorter spine with two teeth at the end, and 

 this again is followed at short intervals by three successively diminishing spines, so short 

 as to be rather called teeth than spines, the first of the three appearing to be a process 

 of the margin itself; between the shaft and this very peculiar spine-row projects the 

 very prominent molar tubercle, its round or oval crown set thickly with rows of sharp 

 teeth, too large to be called denticles ; a process is placed between the molar tubercle 

 and palp, a little to the rear, the shaft behind this appearing to be double-bladed ; the 

 first joint of the palp, which is comparatively long, has at the upper end, projecting from 

 the outer surface, a tooth-like process which seems to be movable ; the second joint, 

 more than twice as long as the first, is rather shorter than the third, and has a short 

 seta at the apex ; the third joint has numerous distally pectinate spines arising not far 

 from the base a little within the inner margin, which they closely fringe at the distal end, 

 those at the apex being long, one at the apex being strongly pectinate on one edge for 

 two-thirds of its length, and more finely pectinate on two edges for the remaining third ; 

 the hind margin not far from the base carries a row of ten or eleven setae, while almost 

 the whole of the outer surface, which is ridged and two-sided, is covered with lines of 

 short spines or denticles. In the Plate the inner surface is shown of the left mandible, 

 the outer surface of the right. 



Lower Lip. — The principal lobes large, together forming a half circle, their inner 

 margins not greatly dehiscent, the inner lobes seemingly adnate to the outer ; the 

 mandibular processes somewhat pointed. 



First Maxillw. — Inner plate narrow, with three plumose setae on the apex ; outer 

 plate long, the apical margin narrow, carrying seven spines, the inner with their bases 

 covered by a brush of cilia ; three of the spines are broken ; all appear to be 

 more or less strongly dentate, the central one having three lateral teeth, the outer- 

 most one or two lateral teeth ; the first joint of the palp is rather broader than the 

 second and about half its length ; the second joint has on its indented apical margin 

 seven spines, pectinate on both edges, and on the surface adjoining these five more, 

 similarly armed but longer and more setiform. 



Second Maxillse:- — The plates broad, the outer broader as well as longer than the 

 inner, the broad distal margins of both fringed with very numerous pectinate spines of 

 different sizes, some large and strong ; the outer and inner margins of both devoid of 

 spines. 



Maxillipeds. — The inner plates comparatively long, yet not reaching far beyond the 

 base of the first joint of the palp, their inner margins fringed far down with plumose 

 setae, which pass on the surface round the inner apex and fringe the outer part of the 

 distal margin, these appearing rather like curved spines than setae; the distal margin 



