60 



THE VOYAGE OF H.M.S. CHALLENGEE. 



very slender form. They are nearly of the same thickness throughout, and rather 

 abundantly furnished with bristles. The terminal joint has not the appearance of a claw, 

 but is linear in shape, and very densely setigerous, more especially at the inner edge, the 

 apex being obtusely rounded. 



The o-ills (see PI. X. fig. 2) occur at the bases of all the legs, except the last, and 

 present alike in their arrangement and structural details a great resemblance to the 

 same organs in Gnathophausia. They are divided into three principal branches, 

 the largest bent in towards the ventral face (see PL IX. fig. 14), whereas the two others 

 are wholly covered by the lateral parts of the carapace. Every branch is more or less 

 distinctly bipinnate, and the pinnulse are divided into numerous rather irregularl}- 

 disposed, lobular projections (see PI. X. fig. 3). In the interior of the lobules small 

 opaque granular bodies are scattered, apparently blood-cells, similar to those ol)served 

 within the several oral parts, and also to some extent within the legs. In the male, the 

 oills (see PL X. figs. 14, 16) are, on the whole, precisely similar to those in the female, 

 excepting that the inner branch (fig. 15) is somewhat larger and more decidedly 

 arborescent, the pinnulse Ijeing in part sul:)divi(led. 



The marsupial pouch in one of the specimens obtained (PL IX. fig. l) is very large, 

 and projects considerably beneath the trunk. As in the Lophogastridte, it is composed of 

 seven pairs of large ovato-lanceolate lamellse, setigerous at their edges (fig. 15), and 

 each overlapping the other in the median line. 



The caudal limbs (PL X. fig. 8), as in tlie Lophogastridae, are develo})ed in both sexes 

 into powerful natatory organs, the terminal branches very slender and sul)divided into 

 numerous short setigerous joints. In the male these limbs (fig. 17) are somewhat more 

 strongly developed than in the female, the liasal part Iteing rather more dilated, and 

 exteriorly jutting out into a rounded lolie. In Ijoth sexes the inner Ijranch is a trifle 

 shoi'ter than the outer. 



The telson (see PL X. fig. 9) is rather elongate and slender, gradually tapering in its 

 outer part toward the apex, which is narrowly truncate. The lateral edges of the telson 

 are in the distal part armed with a row of rather strong but somewhat une(|ual spinules. 

 and two similar but considerably longer ones occur on the apex, in addition to two small 

 bristles in the middle. 



The uropoda. (ibid.) somewhat exceed the telson in length, and have the inner plate 

 lanceolate, the outer rather broader and oldiquely truncate at the apex, or projecting as a 

 short terminal lobe, marked off from the plate by a distinctly defined transverse suture. 

 The outer edge of this plate is perfectly straight and bare, terminating in an obtuse 

 angle, from which issue three short denticles (see fig. 1 1 ). 



The caudal fan of the male agrees precisely in all its details with that of the female. 

 Nervous Si/stem. — In extracting the ventral cord from the specimen selected for 

 anatomical examination, I failed to discover more than seven ganglia belonging to tjic 



