109-1 THE VOYAGE OF H.M.S. CHALLENGER. 



outer edge denticulate ; the spine-row .of four denticulate spines and a small seta ; the 

 molar tubercle prominent, the crown set with numerous denticles which appear to be 

 stronger round the margin than over the concave surface ; there is a feathered seta on the 

 side ; in the right mandible the molar tubercle has, attached to the margin on its outer 

 surface, a small thin plate expanding distally, striated, with finely pectinate edge, similar 

 to that observed in Photis macrocarpus ; a broad-headed process rises near the base of 

 the palp ; the palp is of great size compared with the trunk of the mandible ; the first 

 joint short, widening a little distally ; the second joint long, with seven groups of spines 

 on the hind margin, the front fringed for its whole length with a double row of spines of 

 various lengths, at the lowest part having a row of five which are straight and graduated 

 in length, the lowest the shortest; the third joint shorter than the second, but long, 

 widening distally, with four spines on the outer surface near the base and the outer 

 margin, three on the inner surface also near the outer margin but a little way below the 

 apex, the apex itself set about with many long feathered and pectinate spines, groups 

 of which descend the inner margin 'for three-quarters of its length. 



Lower Lip. — The distal and inner margins of the principal lobes rather flattened, not 

 strongly ciliated ; the inner plates distally broad ; the mandibular processes long, narrow 

 at the tips. 



First Maxillse. — The inner plate small, with the outer margin convex, the inner 

 straight, armed near the apex with a spine-like seta, below which is a much shorter one, 

 the apex narrow and unarmed ; the outer plate has only nine spines on the apical 

 border, three of them apically forked, the rest with one or two lateral teeth on the 

 inner margin ; the long second joint of the palp expands distally, curving over the outer 

 plate, the distal edge having five spine-teeth followed by three more slender, which 

 descend the inner margin, while a series of nine slender plumose spines, beginning on 

 the upper part of the inner margin, crosses the surface towards the outer apex. 



Second Maxillae. — The inner plate shorter and narrower than the outer, fringed 

 with spines round the apex and down the inner margin below the middle ; the broad, 

 slightly convex distal margin of the outer plate fringed with long spines, one series of 

 which passes a little way down the inner margin ; there are none on the outer margin. 



Maxillipeds. — The inner plates oblong, distally a little widened, not quite reaching 

 the apex of the first joint of the palp ; a series of a dozen plumose setae beginning near the 

 middle of the inner margin passes across the inner surface towards the apex ; the slightly 

 convex distal margin has three spine-teeth and six or seven feathered spines ; the outer 

 plates not nearly reaching the distal end of the palp's second joint, with nine spine-teeth 

 along the inner margin, and seven longer spines round the distal border ; the first joint of 

 the palp short ; the second long with many spines on the inner margin, and one or two at 

 the apex of the outer and at a point below it ; the third joint not longer than the first ; 

 scarcely expanded distally, with long spines about the apex and the distal half of the 



