REPORT ON THE AMPHIPODA. 915 



external pointed tooth-like, the internal appearing like concentrically sinuous serrate 

 blades ; there is a small process between the molar tubercle and the base of the palp ; the 

 palp is set just over the molar tubercle, its second and third joints subequal in length, 

 the second with the outer margin more or less concave, and with many spines along the 

 front margin, those near the distal end long ; the third joint having from five to seven 

 on the outer surface near the base, and on the front margin an even row of close-set 

 spines attended by others longer and more widely spaced, and at and near the apex six 

 that are long ; all or nearly all these spines are pectinate, the three terminal more finely 

 than the three below them. 



Lower Lip. — The principal lobes strongly ciliated on the inner part of the distal 

 margin, lightly also on its outer part, little dehiscent ; the mandibular lobes short, 

 squared at the ends. 



First MaxillsB. — Inner plates small, with thirteen (in small specimens seven or eight 

 to ten) plumose setae on the inner or oblique distal margin, those nearest the actual apex 

 the longest, thickest, and most coarsely plumose ; outer plate with eleven strong spines 

 on the obliquely truncate distal margins, some of the spines denticulate for much of the 

 length below the apex, others more strongly denticulate close about the apex ; the second 

 joint of the palp reaching beyond the outer plate, carrying on its distal margin seven to 

 twelve short spines or spine-teeth, with several setae or plumose spines adjoining, and 

 three setae on the outer margin. 



Second Maxillse. — The plates elongate, the inner a little narrower but scarcely 

 shorter than the outer, carrying on its surface a row of fourteen to seventeen plumose 

 setae, the row beginning low down on the inner margin ; the distal margins of both plates 

 carrying numerous spines, those of the outer as usual the longer ; these are curved and 

 finely pectinate ; a few short spines descend the outer margin of the outer, and the inner 

 of the inner plate. 



Maxillipeds. — The inner plates comparatively large, yet scarcely reaching as far as 

 the distal end of the first joint of the palp, carrying several plumose setae on the inner 

 margin, and smaller incurving plumose setae or spines on the distal, and distal part of 

 the outer, margin ; the truncate distal margin has three strong triangular teeth, and a 

 fourth is inserted just below its inner apex on the outer surface ; the outer plates not 

 reaching the distal end of the second joint of the palp, having the inner margin bordered 

 with eighteen rather long spine-teeth, succeeded round the distal margin and distal half 

 of the outer, by eight or ten plumose setae ; there are also numerous groups of setae on 

 the outer surface in the neighbourhood of the inner margin for almost its whole length ; 

 this outer surface is figured on PI. LXXV.; the first joint of the palp is short, with setae 

 on the inner margin and outer apex ; the second joint broader and much longer, with 

 numerous setae in a row along the inner margin, in groups upon the surface and outer 

 margin ; the third joint longer than the first, with several groups of setae upon the surface 



