355 



8. Stenopleustes Malmgreni (Boeck). 



(PI. 125, fig. 1.) 

 Amphithopsis Malmgreni, Boeck, Crust, arnph. bor. & arct. p. 119. 



Body very slender and perfectly smooth, the back being evenly 

 rounded throughout. Cephalon about the length of the first 2 segments of 

 mesosome combined, rostral projection rather short and blunt at the tip, 

 lateral corners distinctly angular. Anterior pairs of coxal plates but little 

 deeper than the body, and successively increasing in size to the 4th; 1st pair 

 scarcely expanded in their outer part, and having the distal edge evenly 

 curved, without any dentiform projection at the infero-posteal corners ; 4th 

 pair broadly rounded at the tip, posterior edge below the hind projection 

 somewhat oblique; the 2 succeeding pairs with the posterior lobe much deeper 

 than the anterior and obtusely truncated at the tip. Last pair of epimeral 

 plates of metasome nearly rectangular. Eyes very large, reniform, nearly 

 occupying the entire height of the cephalon, visual elements very distinct, 

 pigment light red. Superior antennae extremely slender and elongated, attain- 

 ing the length of the whole body, 1st joint of the peduncle about the length 

 of the other 2 combined and rather thick, flagellum nearly 6 times as long 

 as the peduncle, and having the 1st joint much elongated. Inferior antennae 

 scarcely more than half as long as the superior, last joint of the peduncle 

 exceeding in length the penultimate one, flagellum about l l /z times as 

 long as the peduncle. Anterior gnathopoda somewhat smaller than the 

 posterior ones, propodos in the former scarcely as long as the carpus, and 

 oblong oval in form, with the palm very oblique and bordered with several 

 spines; that of the posterior ones fully as long as the 2 preceding joints com- 

 bined. Pereiopoda very slender, and edged with tufts of small spines, basal 

 joint of the 3 posterior pairs rather large and oval in form, with the hind edge 

 smooth. Last pair of uropoda with the inner ramus 3 times as long as the 

 basal part, outer ramus much shorter, both edged with strong spines. Telson 

 rather small, oblong triangular in form, gradually tapering distally, tip ob- 

 tusely rounded. Body pellucid, whitish, sometimes with a faint tinge of 

 flesh-colour, but without any trace of true pigmentary ornament. Length 

 of adult female 7 mm. 



Remarks. This form was erroneously referred by Boeck to his 

 genus Amphifhopsis, the type of which, according to that author, is A. longi- 

 caudata, and it was thus placed in an entirely different family, viz., that of 

 the Ahjlida. Boeck moreover referred to the same genus 2 other species, 

 which evidently belong to the present family, and which will be described 

 farther on as species of the genus Parapleustes Buchholz. The present spe- 



