REPORT ON THE AMPHIPODA. 1435 



and not very much shorter than the two together ; the third joint is thinner than the 

 second, very little shorter, with a narrow curved tip ; the hind margin of each joint is 

 convex ; the second forms an angle with the first by bending backwards, the third with 

 the second by bending forwards. 



Lower Lip. — The principal lobes broad, well ciliated, dehiscent, the connecting 

 band having a scabrous ridge at the centre on the inner surface ; the mandibular 

 processes rather broad. 



First Maxilla'. — The outer plate has a row of setules or very thin spines on the inner 

 margin, which are followed by seven spines along the obliquely sinuous apical margin, 

 the three on the actual apex being much stouter than the rest ; a second row of setules 

 is planted on the surface at a little distance from the spines ; the one-jointed palp is 

 narrower than the plate but reaches a little beyond it ; it has five little apical spines, 

 one or two on the lateral margin, and setules on the outer margin. 



Second Maxillae. — Both plates tapering, tipped with small spines and fringed with 

 setules ; the outer plate the longer. 



MaxUHpeds. — A narrow stem rising from a broad base carries a pair of slender 

 outer plates, set close together, tapering, fringed on or near the outer margin with hair- 

 like spinules, and having a little tooth on the inner margin near the apex ; the inner 

 plate is rather more than half as long as the outer, set with hair-like spinules ; its apex 

 rounded, the plate itself springing unjointed from the strongly curved central ridge of 

 the stem. The figure mxp.B., representing the outer surface, is taken from a female 

 specimen. 



First Gnathopods. — Side-plates not distinct from the segment. The first joint of 

 these diminutive limbs is as long as the remaining joints united, adapted for gland- 

 cells, the front margin convex, carrying some minute setules, the hind margin sinuous ; 

 the second joint cpiite short ; the third joint not much longer, apically acute, most of 

 it lying on the inner side of the wrist ; the wrist shorter than the hand, widening 

 distally, fringed on and about one margin with short spinules, the other slightly furry ; 

 the hand near the base about as wide as the wrist, with convex margins, the distal half 

 tapering, the margins fringed with spinules or setules, of which there is a third row on 

 a ridge of the hand's inner surface ; the finger not half the length of the hand, socketed 

 in the apex of the hand and bending over in the specimen figured, so as to be scarcely 

 visible, Milne-Edwards was only able to distinguish four joints in these and the 

 following gnathopods, " the first long and cylindrical, the two following very short, and 

 the last large, flattened, lanceolate, ending in a very sharp point." 



Second Gnathopods. — The branchial vesicles longer and much broader than the first 

 joint of the limb, having like the following pairs several subsidiary folds or pockets down 

 the centre. The side-plates not distinct from the segment, covered with scale-like 

 markings ; the segment above each side-plate sending out a strong interlocking process 



