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



spines being to some extent denticulate or pectinate ; tlae molar tubercle is prominent, 

 with oval crown, dentate on one side, ciliated along the other edge ; at the top in front 

 a tubercular process and a ciliated ridge at right angles to the crown ; there is a broadly 

 oval process between the molar tubercle and the palp ; on the outside from the basal 

 part of the shaft, and parallel with it, projects a large, rectangular process, probably 

 servinw some interlocking purpose to adjust or strengthen the movements of the 

 mandibles ; the first joint of the palp has a group of spines at the outer distal angle ; 

 the second joint has the hinder margin concave, with spines along the convex front 

 margin, except a short piece at the base, and a parallel row on the surface, many of the 

 spines being very long and most of them pectinate on two edges ; the third joint is 

 narrow, tapering, longer than the first and second united, with pectinate spines of 

 various lengths along almost the whole front margin, with groups also at the back and 

 one on the surface near the base, also with closely-set cilia on the surface of the ujaper 

 part. 



Lower Lip. — The principal lobes broad and deep, and rather thick, strongly ciHated 

 on the broad, rounded, distal margin, and more slightly on the straight inner margin ; 

 the mandibular processes with the apex directed a little outwards, the outer margin 

 being broadly grooved, so tliat the process has a three-sided appearance. 



First Maxillie. — The inner plate oblong-oval, the attachment below narrow, the 

 outer margin overlapping the outer plate ; seven plumose setse, commencing at the top 

 of the inner margin, pass round half the broad, distal margin, the seventh arising on the 

 surface a little within the margin ; at the inner corner there are three setules ; the 

 outer plate, longer but scarcely broader than the inner, carries on the truncate distal 

 margin eleven slightly curved spines, of which none seems to have more than two 

 lateral denticles, most of them having only one ; on one of the maxillse there appeared 

 to be twelve spines ; the first joint of the palp is short, the second reaches beyond the 

 outer plate, and carries round the apex and top of the inner margin seven long spine- 

 teeth, the apex itself being serrate or rather cut into broad teeth ; eight setiform spines 

 pass along the surface from the outer apical angle a little way down the inner margin, 

 within much the same limits a small thicket of cilia occupying the opposite surface ; on 

 the outer margin seta-like spines are placed at four serrations and at the apex. 



Second Maxillae. — The inner plate has its inner margin for some distance straight, 

 strongly ciliated, at the widest part of the plate the margin turns obliquely towards the 

 rounded apex, having at the turn several plumose setae, numerous long and slender 

 spines fringing the margin from this point round the apex ; the outer plate is very 

 little longer than the inner and scarcely so broad, both its front and hind margins 

 concave below and convex above, the convex portions and the apex fringed with 

 numerous spines, those on the apex very long, those on the outer margin small. 



Maxillipeds. — The inner plates small, reaching little beyond the base of the first 



