developed, extending beyond the middle, and reappearing for a short distance in 

 the hindmost part; pseudorostral projection not much produced, almost horizontal, 

 and obtuse at the tip, terminal edges cut off into 5 denticles ; antero-lateral 

 corners somewhat produced. Carapace of male quite smooth, with only a single 

 small denticle at the end of the frontal lobe; pseudorostral projection obtusely 

 rounded at the tip, with the terminal edges smooth; antero-lateral corners blunted. 

 1st pair of legs rather feeble, with several plumose setae outside the terminal 

 part, penultimate joint nearly as long as the antepenultimate; 2nd pair with the 

 last joint about the length of the 2 preceding joints combined, and linear in 

 form, with about 8 unequal spines. 3rd pair in male with 2 comparatively short, 

 falciformly curved appendages of the ischial joint. Uropoda rather slender, with 

 the rami much narrower than in the 2 preceding species, the inner one 

 with the distal joint scarcely shorter than the proximal one, and armed with 

 5 or 6 spines, the outermost very much elongated; outer ramus with scattered setse. 

 Colour bright fulvous, somewhat lighter in male. Length of adult female scarcely 

 5 mm., of male 5 J /2 mm. 



Remarks. This form, in the fresh state, is at once recognized by its 

 beautiful bright orange or fulvous colour, a character which has indeed given 

 rise to the specific name. The species is also otherwise easily distinguishable 

 from the 2 preceding ones, both as regards the general form and the structure 

 of some of its appendages, especially that of the uropoda. 



Occurrence. I found this form many years ago rather plentifully at the 

 Lofoten Islands, in a depth of from 6 to 12 fathoms sandy bottom covered with 

 a thin layer of mud, and have subsequently also met with it in several places of 

 the Finmark coast, as far east as Vard0 ; but south of the Lofoten Islands, I have 

 never come across it, and we must conclude from this, that it is a true Arctic form. 



Distribution. Iceland, at Rejkjavik. Spitsbergen (Norw. North Atlantic 

 Expedition). 



4. Leueon pallidus. CI. 0. Sars. 



(PL XXV.) 



Leueon pallidus, G. 0. Sars, Om den aberrante Krebsdyrgruppe Cumacea og dens nordiske 



Arter, p. 57. 



Specific Characters. Body slender and highly compressed, with the tail about 

 the length of the anterior division. Carapace in female somewhat exceeding the 

 length of the exposed part of the trunk, dorsal crest very fully developed, extending 

 to the hind edge; pseudorostral projection considerably produced, horizontal, at- 



fi Crustacea. 



