226 



on a closer examination, will turn out to constitute types of distinct, though 

 nearly allied genera. This may especially he the case with the 2 species from the 

 Challenger Expedition, N. lateralis and globular is, both of which were found on 

 Euphaiisiidse. The species described from the Norwegian North Atlantic Expedi- 

 tion as A T . .clypeata, seems to agree more closely with the type species, though this 

 form, too, exhibits some rather pronounced peculiarities. The Norwegian species, 

 described below, is the first one recorded, and must accordingly be regarded as 

 the type of the genus. 



Notophryxus ovoides, G. 0. Sars. 



(PI. XCV). 



Notophryxus ovoides, G. 0. Sars. Oversigt af Norges Crustaceer 1, 



p. 71, PL II, figj. 9—11. 



Specific Characters. — Body of fully grown female ovoid in outline, some- 

 what widening behind, with the cephalic part projecting in front as a broadly 

 rounded prominence, scarcely at all deflexed. Dorsal face of mesosome 

 slightly convex, with the segments only visible along the middle, lateral parts 

 strongly tumefied, and projecting posteriorly beyond the tip of the metasome. 

 Ventral face canaliculate along the middle, and forming in front a comparatively 

 small rounded oral area, abruptly contracted behind. Metasome constituting a 

 short, semicircular deflexed plate, with only slight traces of segmentation. 

 Marsupial cavities nearly contiguous along the middle of the ventral face, their 

 posterior openings pushed on to the dorsal side. Antennae imperfectly defined, 

 lamelliform, constituting together a broad horizontal plate defining the oral area 

 in front, and deeply incised in the middle, to receive the oral cone. — Body of 

 young female narrower, oblong oval in form, with the metasome more distinctly 

 segmented and projecting behind, being strongly curved downwards. — Adult male 

 narrow linear, resembling in shape that of Dajus mysidis; metasome, as in the 

 latter, undivided. Colour of female pale yellow, with short reddish orange trans- 

 versal bands across the median part of the back. Length of fully grown female 

 3V2 mm., of male 1 mm. 



Remarks. — This form was described by the present author in the year 

 1882, but was at that time not subjected to a more detailed analysis, for which 

 reason several peculiarities had escaped my attention. The description and figures 

 now given are based upon a very close examination of several specimens, one 

 of which was carefully dissected, in order to assertain some difficult points, especi- 



