REPORT ON THE AMPHIPODA. 1355 



Upper Antennas. — The peduncle short, the first joint not longer than broad, but 

 longer than the two following together ; the first joint of the flagellum very elongate, the 

 brush composed of more than forty rows of filaments, the apex of the joint produced to a 

 point which almost reaches the apex of the third joint ; the second joint not half the breadth 

 of the first, not longer than broad, carrying three groups of filaments; the third joint 

 narrower, also carrying filaments; the fourth, fifth, and sixth joints successively narrower 

 and longer; the two terminal joints also narrow, neither of them longer than the 

 sixth. 



Lower Antennas. — Although the upper pair are so powerfully developed, the lower, as 

 far as can be seen in the mounted specimen, consist each of a single narrow joint. 



Hie Ghwthopods are nearly of the usual character, the wrist not longer than the hand, 

 with the produced portion very short. 



The First and Second Peraeopods have the hind margin of the first and second joints 

 produced apically into a narrow acute tooth. 



Third Peraeopods. — There is an acute tooth at the apex both of the front and the hind 

 margin, that on the front the smaller and lower ; the second joint has its front margin 

 produced into an acute tooth ; the fourth joint is considerably longer than its greatest 

 breadth, the small apical tooth of the front margin not reaching so far as the much 

 smaller tooth within the palm, this tooth being separated from it by a narrow but deep 

 cavity, and followed by a small cavity, beyond which comes the usual crenulate margin 

 leading towards the hinge ; the fifth joint is subequal in length to the fourth, curved, 

 with a very slight bulging of the smooth inner margin in one of the limbs, while in the 

 other this margin is simply concave ; the finger is minute, of the usual form. 



Fourth Peraeopods. — The first joint rather longer than the branchial vesicles, not 

 quite so long as the first joint in the third pair, the front margin produced into a sharp 

 narrow tooth ; the second joint much narrower than the first, apically produced into a 

 sharp tooth in front ; the third joint having a small sharp tooth at the top in front ; the 

 fourth joint more than twice the length of the third. 



Fifth Peraeopods similar to the fourth, with the usual variations in the length of the 

 joints, and the first joint broader than the broad first joint of the preceding pair, the 

 teeth of the first, second, and third joints somewhat more pronounced. The male genital 

 organs which have their opening in the seventh perseon-segment are fully developed and 

 conspicuous through the transparent integument. 



Pleopods. — Peduncles broad ; ten joints in each ramus, the first not very long. 



Uropods. — The inner ramus of the second pair more than half the length of the outer, 

 not reaching to the apex of the peduncle of the first pair, whde the outer ramus reaches 

 beyond that apex. 



Length, without the antennas, rather more than two-fifths of an inch. 



Locality. — Station 272, September 8, 1875, Mid Pacific; lat. 3° 48' S., long. 



