REPORT ON THE SCHIZOPODA. 135 



36. JSfematoscelis rostrata, G. 0. Sars (PI. XXV. figs. 8-10). 



Xematnacelis mstrata, O. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 34. 



Specific Characters. — Form of body much shorter and stouter than in the List 

 species. Carapace with a very strong lateral denticle at posterior part of inferior 

 margin, and a conspicuous rounded crest above anterior to the middle ; rostrum 

 greatly produced, reaching almost to the end of the basal joint of the antcnnulae, 

 straight, acuminate, broad and flattened at the base. Caudal segments smooth above, 

 with small rounded epimera. Eyes rather large, irregularly pyriform, cornea narrowed 

 in upper part. Antennal scale comparatively small, reaching scarcely to the end of 

 the second joint of the antennular peduncle. First pair of legs shorter than in the 

 other species, meral joint reaching hardly to tip of antennular peduncle, propodal 

 joint longer than carpal, terminal joint slightly dilating toward the tip, with five spines. 

 Gills and caudal fan as in Nematoscelis tenella. Length 8 ram. 



Remarks. — This form also, it would seem, is represented in the collection only by 

 immature specimens. I have nevertheless felt warranted in establishing a new species 

 for their reception, differing, as they do, in several respects distinctly from any of the 

 preceding species. Thus, the l:)ody is comparatively much shorter, the rostrum more 

 produced ; and besides, the strongly developed lateral denticle of the carapace, as also- 

 the conspicuous dorsal crest, would seem to aiford well-marked specific characters. 



Description. — The length of the specimens in the collection does not exceed 8 mm., 

 and therefore this form must be regarded as one of the smallest Euphausidians. All the 

 specimens are females. 



The form of the body (see PI. XXV. fig. 8), as compared with that of Nematoscelis 

 tenella, is much shorter and more thickset, as also somewhat compressed. 



The carapace is comparatively short in proportion to its height, and has on either side 

 a very strong lateral denticle, jutting out from the hinder part of the inferior margins 

 about where that corresponding to it projects in Nematoscelis tenella. On the dorsal 

 face, moreover, a very conspicuous rounded crest occurs at some distance in front of the 

 middle, disappearing before it reaches the base of the rostrum. The latter is greatly 

 produced, extending far beyond the middle of the basal joint of the autennulai, and is 

 quite straight, ending in a sharp point. Viewed from above (fig. 9), the rostrum appears 

 broad and flattened at the base, tapering gradually toward the extremity. 



The caudal segments are smooth above and appreciably broader than in the last 

 species, the epimera, however, being very small. The last segment is longer than the 

 preceding, aud has a very small simple preanal sjiine. 



The eyes (see figs. 8, 9) are comparatively large, irregularly pyriform, and slightly 

 flattened, with the cornea oblong in form and somewhat narrowed in its upper part. 



The antennular peduncle {ibid.) appears a trifle less elongate than in Nematoscelis 

 tenella, for the rest exhibiting a very similar structure. 



