REPORT ON THE AMPHIPODA. 1299 



scarcely longer than broad ; the third joint longer than in the preceding pair, rather 

 shorter than the fourth joint, which has a little spinule at the apex of the straight front 

 margin, and a scarcely developed tendency to pectination ; the fifth joint curved, 

 considerably longer than the fourth, the concave front margin with fine decurrent 

 pectination ; the finger rather more than a quarter the length of the fifth joint, armed 

 like that of the preceding perseopods. 



Fourth Perseopods. — Side-plates bilobed. Branchial vesicles widened above, narrowed 

 below, rather longer than the first joint. The first joint much larger than in the preceding 

 pair, with six spines along the front margin, the hind margin smooth, scarcely convex 

 except at the two extremities ; the rest of the limb similar to the preceding pair, except 

 that the fourth joint is more decidedly though very finely pectinate, and the fifth joint is 

 longer. The first and fifth joints being longer, and the others certainly not shorter than 

 in the preceding pair, it follows that the whole limb is longer than that of the third 

 perseopods. 



Fifth Per&opods not much longer than the first joint of the fourth. The first joint 

 twice as long as the remaining joints together, broad, looking very like a branchial 

 vesicle, the front margin convex, with four little spines on the lower part, the apex 

 drawn down a little below the hind margin, which is almost straight except at the two 

 extremities ; the second joint as broad as the length, with a subapical spine on the front 

 margin; the third joint narrower, not longer, than the second ; the fourth a little longer 

 than the second; the fifth narrower than the fourth, not longer than the third; the sixth 

 about as long as the fifth, tapering slightly to a blunt end, the front corner angled, 

 furry, with a minute spinule at the angle. 



Pleopods. — Coupling spines small, the apices forming as it appears a circlet of 

 retroverted teeth, below which is another group of smaller teeth ; the cleft spine without 

 any considerable dilatation of either arm; the first joint of the inner ramus having three 

 plumose setae on the inner margin below the cleft spine; the first joint of the outer ramus 

 with a short, broad, interlocking process, apically narrowed, the outer margin of the joint 

 having several plumose setae ; the joints of the inner ramus nine to ten, of the outer ten 

 to eleven. The terminal joint of the outer ramus in two or three instances in this 

 specimen had but one seta instead of two, an anomaly which I have nowhere else 

 observed. 



Uropods. — Peduncles of the first pair subequal in length to the rami, the outer 

 margin pectinate, the inner with an acute apex ; the rami lanceolate, reaching beyond 

 those of the third pair, the outer a little the shorter, pectinate along the outer margin and 

 having five larger teeth on the lower part ; the inner margin with two teeth and a little 

 pectination ; the inner ramus very similarly armed, but with four teeth on the inner 

 margin ; peduncles of the second pair much shorter than those of the first, shorter than 

 the rami ; the rami reaching beyond the peduncles of the third pair, much shorter than 



