REPORT ON THE AMPHIPODA. 821 



above a shorter broader piece cut distally into three denticles ; the .spine-row appears to 

 consist on this side of only seven spines ; the palp, much longer than the body of the 

 mandible, is attached to the front over the base of the cutting edge ; the first joint 

 is short, though not unusually so ; the second is broader, l)ut slightly shorter, than the 

 third, carrying three or four short sette on the outer margin ; the long slender third 

 joint has its sides unarmed, and carries ten spines of different lengths on the obliquely 

 truncate definite a^jical margin. In Phoxus ^ihmiosus Kr0yer describes the molar 

 tubercle as insignificant, without teeth, but furnished with three or four long and strong 

 setse. 



Loiver Lip. — The plates are very broad at the base, with small and narrow 

 mandibular processes, the forward lobes being rounded, not strongly ciliated, though 

 some of the cilia are long, the rounded apical margin being produced on the inner side 

 into a conical tooth traversed by a duct which apparently opens at the apex of the 

 tooth. 



First Maxilla}. — Inner plate with sinuous inner margin carrying a spiniform cilium, 

 above which is a plumose seta, followed at a distance on the apex by a larger one ; 

 outer plate short, carrying on the truncate apex nine spines, three pairs with one spine 

 long and multidentate attended by a short one with a single lateral tooth, and an outer 

 group of three in which the longest and strongest is not denticulate ; the long rather 

 narrow second joint of the palp overtopping the outer plate, and carrying a double row 

 of slender spines ou its apex. The border which connects the two members of this pair 

 of maxillae is surmounted by a row of seven setse. 



Lower Maxilla. — The plates are somewhat curved, the inner not much shorter 

 than the outer, with ten or eleven plumose setae round the upper part of the inner 

 margin and the rounded apex, several of them being pectinate in the upper part as well 

 as plumose ; the longest are not those lowest on the inner margin, but the two placed 

 where the inner margin passes into the apical ; the outer plate has some sixteen spines 

 or setse passing round the apex and upper part of each lateral margin, the smallest of 

 the spines being on the outer side. 



Maxillipeds. — The inner plates not reaching nearl}^ to the end of the first joint of 

 the palp, the inner margin unarmed, the rounded apex carrying four plumose setse, the 

 outer surface having a single spine-tooth just within the inner margin and below the 

 apex ; the outer plates long and narrow, reaching to the middle of the second joint of 

 the palp, armed on the inner margin with some fourteen spine-teeth and round the 

 outer margin with long plumose setas, about seven in number; the spine-teeth gradually 

 increase in size to the apical one, which is the largest, each near its own apex being 

 delicately pectinate on both sides for a short distance, some of the upper being also 

 slightly plumose; the first joint of the palp is almost as long as the third, the second is 

 nearly twice as long, armed ou the inner border with numerous pairs of spines ; the 



