REPORT ON THE AMPHIPODA. 1429 



following joint though not so broad ; the fourth joint also differs from that of the 

 preceding pair as well by its much smaller size as by having four teeth instead of six, 

 graduated in size, the outermost being the longest ; the finger-formed hand is not so long 

 as the first joint, and has a pectination on the surface near and parallel with its concave 

 front margin ; the finger is here distinct, though very small, its concave front margin 

 not continuous with that of the fifth joint. The produced front apex of the third joint 

 in this hrnb seems to have suggested the name longispina, which Mr. Spence Bate has 

 given to a species of Phrosina, but the character is shown in Milne-Edwards' figure of 

 Phrosina nic&ensis, and is found in all the Challenger specimens of the genus, although 

 the process does not quite attain to the length shown in the figure of Phrosina longi- 

 spina ; as the process not uncommonly lies against the fourth joint, it easily may be, 

 and no doubt often has been, overlooked. 



Fifth Perseopods. — The side-plates with sinuous front and lower margins at right 

 angles, connected by a very convex hind margin ; the limb reduced to a simple mem- 

 branous plate, the front margin slightly convex, with a minutely pointed apex, the hind 

 margin almost semicircular but widening out at the two ends. I can perceive no trace 

 of a second joint, other than a little semicircular mark which scarcely reaches the small 

 cavity between the apex of the front margin and the bend of the hind margin to meet it. 



Pleopods. — The two coupling-spines very small with the usual inverted saucer-like 

 head, and having a lateral saw of four teeth, certainly on one, probably on either edge ; 

 the cleft spine with stout shaft, the two arms slender, short, equal in length ; the joints 

 of the rami ten to eleven, the first joint in each narrow at the base, then widening ; the 

 first joint of the outer ramus having the not uncommon twisted connecting process 

 descending from the peduncle and directing its narrow apex towards the inner ramus. 



Uropods. — The two long distally rounded plates of the first pair are slightly longer 

 than, and not so broad as, those of the third pair, with minutely pectinate edges ; the two 

 plates of the second pair are shorter than either those of the first or third. All the six 

 plates more or less overlap, their broadly rounded ends being of great tenuity, and often 

 showing prismatic colours ; they are diversified by irregular markings, the third pair 

 having stellate markings on the lower part. 



TJie Telson, a little longer than broad, about two-sevenths of the length of the third 

 uropods, a half-oval, difficult to distinguish, owing to its thinness, divided by a very fine 

 line from the preceding segment of the pleon. 



Length. — The specimen, in the position figured, measured in a straight line rather 

 more than one-fifth of an inch. 



Locality. — The specimen here described was obtained in the North Atlantic, from the 

 surface, at night, April 29, 1876; lat. 18° 8' N., long. 30° 5' W.; surface temperature, 

 73°7. Another was taken in the North Atlantic, June 18-19, 1873; lat. 35° 18' N., 

 long. 51° 42' "W., also at the surface; surface temperature, 71°. 



