REPORT ON THE AMPHIPODA. 649 



be exactly made out, seemingly of the usual form ; secondary plate of left mandible 

 very small, strap-shaped, curved, microscopically dentate at the apex ; spine-row of three 

 very small curved spines close together ; molar tubercle prominent, the dentate crown 

 showing some fourteen or fifteen transverse blades, and set round the edge with prominent 

 teeth pointing in towards the blades ; articular condyle large ; the palp set just over 

 the molar tubercle; some eighteen spines form a row on the upper part of the second 

 joint ; there are twenty-two spines on the inner border of the third joint, beginning 

 below the middle, and one spine near the outer border and the base ; the third and first 

 joints together about equal the length of the second. 



Lower Lip. — Forward lobes but little dehiscent distally, overlapping below when 

 flattened, inner and apical margins ciliated, but not the outer margins ; margins of the 

 mandibular processes ciliated. 



First MaxillsB. — Inner plate narrow at the apex, tipped with two plumose setae; outer 

 plate long, apical margin fringed with six strong dentate spines, with four, more slender, 

 below them, and the eleventh, a strong one, standing a little apart from the rest on the 

 inner margin; those in the left maxilla (figured on the right-hand side of the Plate), 

 seem to have been much more worn than those in the companion maxilla, a rather odd 

 circumstance; the first joint of the palp'very short, the second long, of almost uniform 

 width, in the left maxilla showing twelve spiniform teeth on the apex, while on the other 

 maxilla there are only nine ; in each there is also a plumose seta. 



Second Maxillas. — The plates slender, the outer broader, very little longer than the 

 inner ; the apical margins of both very oblique, the fringe of the inner plate being 

 bounded by a plumose seta much longer than the adjacent spines. 



Maxillipeds. — Inner plates with plumose setse on the inner margin, nine in number, 

 diminishing in size towards the apex, which they reach before the series is continued 

 towards the outer corner by one or two additions ; the apical margin has three teeth, 

 the innermost the largest, below which is a smaller spine-tooth ; on the outer side of the 

 three is a curved spine ; the plates themselves, though fiat on the inner surface, on the 

 outer are so strongly ridged as to be in fact longitudinally three-edged rather than 

 laminar, answering to the epithet " prismatic" applied by Kr0yer to the corresponding 

 plates in his Anonyx edivardsii; they reach beyond the first joint of the palp ; the outer 

 plates reach as far as the apex of the second joint of the palp ; on the inner margin are 

 four long setse among cilia followed by a long spine, and this by thirteen close-set 

 nodulous teeth, the two uppermost and largest of which may be reckoned as apical ; 

 these are followed by a pectinate spine-tooth ; on the outer surface away from the margin 

 are seven spines of some length ; of the palp the first joint is short, the second not very 

 greatly longer ; the finger is short, with a narrow nail set among cilia ; the dorsal cilium 

 is midway between the base of the finger and the base of the nail. 



First Gnathopods. — Side-plates leaving the head and mouth-organs almost entirely 



(ZOOL. CHALL. EXP. — PART LXYII. — 1 887.) Xxx 82 



