CEUSTACEAKS FEOM THE TKOPICAL ATLANTIC. 357 



than the preceding tour together, and represents the flagelium in an early stage. The 

 condition of these antennae indicates that the specimen is a male not fully adult. 



The first gnathopods have the fifth joint rather longer than the sixth. As in the 

 other limbs there is scarcely any armature, but the short fourth joint has a few spinules 

 and the two following joints a few slender setse. 



The second gnathopods have the second joint rather longer than that in the first pair, 

 the fourth joint smooth, the fifth shorter than the sixth. 



The first perseopods have the fourth joint much longer than that of the gnathopods, 

 but much shorter than the fifth joint, which is dilated and almost entirely glandular; 

 the following joint is slender. 



The second pereeopods scarcely diff'er from the first, except in having the fifth joint 

 not dilated. 



The third perseopods have the second joint longer than all the rest of the limb, with 

 spine-like serrations on both margins, those on the front the stronger. The apical 

 tooth is produced much beyond the short third joint. The fourth joint is decidedly 

 longer than the fifth, which is not quite three times as long as the sixth. The finger 

 is minute and bent. 



The fourth perseopods have the second joint little more than half the length of that 

 in the preceding pair ; the fourth joint longer than the fifth, and these two together a 

 little lono-er than the second. The sixth joint is half as long as the fifth. The finger 

 is very small, strongly curved. 



The fifth perseopods are slender, about half as long as the fourth, and a third as long 

 as the third pair. The fourth, fifth, and sixth joints are subequal one to another, and 

 two of them together are subequal to the second joint. The finger is minute, seemingly 

 retractile. 



The first uropods are rather longer, while the other two pairs are rather shorter, than 

 half the upper antennae. In all, the peduncles are elongate, but shorter than the 

 coalesced inner ramus. The outer ramus in the first two pairs is like a small spine ; in 

 the third pair it is slender, but rather longer than half the inner ramus. The marginal 

 armature in all three pairs is extremely minute, except for a single spine or process on 

 the inner margin of the first pair a little higher up than the outer ramus. 



The total length a little exceeds a fifth of an inch, the measurement without the 

 antennae and the uropods being just one tenth of an inch. 



Habitat. Atlantic. Lat. 7° 1' 1" N., long. 15° 54' W. Taken in the daytime from a 

 depth of 100 fathoms. 



Branchial vesicles were present on the first, second, third, and fourth perseopods, 

 but not on the second gnathopods. No stress, however, can be laid on this deficiency, 

 since on one side of the specimen the vesicles were absent also from the first and 

 second perseopods. 



From Scina atlantica (Bovallius), to which the present species makes the nearest 

 VOL. XIII. — PART X. No. 2. — Fehruary, 1895. 3 f 



