132 THE VOYAGE OF H.M.S. CHALLENGER. 



The form of the body (see PI. XXV. fig. 1), as compared with that of the preceding- 

 species, appears somewhat more slender, and less dilated anteriorly. 



The carapace lacks, as in that species, every trace of lateral denticles, and is some- 

 what more elongate in proportion to its height. The anterior part is very slightly 

 keeled above, and juts out as an acute rostral projection, reaching beyond the middle of 

 the basal joint of the antennulse. This projection, too, is quite straight, with the basal 

 part rather broad and flattened. The antero-lateral corners of the carapace are not 

 nearly produced to the same extent as in Nematoscelis megalops. 



The caudal segments are perfectly smooth above, none of them being keeled as in 

 the preceding species. The epimera are comparatively small and evenly rounded. The 

 last seoinent is rather elongate, and exhibits a very small simple preanal spine. 



The eyes (see fig. 2) are not nearly so largely developed as in the last species, being 

 comparatively smaE, with the cornea somewhat narrow^ed in its upper part. 



The antennular peduncle (ibid.) exhibits a structure closely resembling that in 

 Nematoscelis megalops, but ha\dng the two outer joints a trifle more elongate. 



The antennal scale (ibid.) does not nearly reach the tip of the antennular peduncle, 

 and would seem on the whole to be apparently less slender than in the last species, with 

 the apex obtusely rounded and the outer corner but slightly projecting. 



The first pair of legs (see fig. 1) are rather slender and elongate, though not nearly 

 to the same extent as in the last species, being, when fully extended, somewhat shorter 

 than the body. Of the joints the meral, as in that species, is liy far the longest, reaching 

 a little beyond the tip of the antennular peduncle. The relation in size between the two 

 succeeding joints is, on the other hand, somewhat difierent from that in Nematoscelis 

 megalops, the propodal joint being the longer of the two. Finally, the terminal joint 

 (fig. 3), though comparatively small, is somewhat more fully developed than in the above- 

 mentioned species, and also, it would seem, very movably connected with the preceding 

 joint. It exhibits an oljlong form, being slightly dilated in the middle and constricted 

 at the base, and has six very unequal spines, one of which is very large and strong, 

 projecting far beyond the rest. No spines arise, as in Nematoscelis megalops, from the 

 end of the preceding joint. 



The succeeding pairs of legs, as also the gills and the pleopoda, would seem to agree 

 in all respects with those of Nematoscelis megalops. 



The telson (see fig. 4) appears somewhat less elongate than in that species, exhibiting, 

 however, for the rest, a very similar aspect. 



The uropoda {ibid.) have the inner plate somewhat longer than the outer, projecting 

 however but very little, if at all, beyond the tip of the telson. 



One of the specimens, mounted in Canada balsam on a glass slide, is ovigerous. The 

 ova, which arc rather numerous, lie enclosed within a single oblong ovisac, extending 

 beneath the trunk, almost throughout the whole of its length (see fig. l). 



