128 



to he identical with a form previously described hy the present author as a 

 species of the genus Desmosoma. Though this form on the whole agrees very 

 closely with the 2 above-described species, yet there are at least 2 characters, 

 in which it differs very markedly, viz.. the structure of the 1st pair of legs and 

 that of the uropoda, and for this reason I think it right to maintain the genus 

 proposed by Prof. Meinert, the more so as I have found it advisable to raise 

 another species, previously referred by me to the genus Desmosoma, to the rank 

 of a distinct genus. 



Eugerda tenuimana, G. 0. Sars. 



(PI. LV.) 



Desmosoma Icniiliitauum, G. 0. Sars, Beretiiing om en i Sommeren 18(55 foretagen zool. Reise 

 ved Kysterne af Christianias og Christian sands Stifter, p. 33. 



Sj'n : Eugerda ylobiceps, Meinert. 



Specific Characters. Body slender and elongated, more than 4 times as 

 long as it is broad, with a very conspicuous constriction between the 2 sections 

 of mesosome. Cephalon of a similar form to that in Desmosoma lineare, though 

 comparatively somewhat larger. Anterior section of mesosome about the length 

 of the first 2 segments of the posterior combined, and, in female, "somewhat 

 broader than the latter; 1st segment in both sexes much smaller than the 3 suc- 

 ceeding ones, which are produced on each side to acute anteriorly-pointing lappets 

 assuming in male a spiniform appearance. The 3 posterior segments of mesosome 

 laminar, sub-quadrate in outline, and somewhat broader in male than in female; 

 antero-lateral corner of 5th segment not produced. Caudal segment in female 

 oval, narrowly rounded at the tip, in male almost quadrate in outline, tip blunted, 

 lateral corners rectangular. Superior antennce 6-articulate. Inferior antennas in 

 female very slender, considerably exceeding half the length of the body, flagellum 

 about the length of the peduncle, and composed of about 16 articulations; those 

 in male transformed in a manner similar to that in the male of Desmosoma lineare, 

 though less strongly built: 2nd joint of the peduncle armed outside with a single 

 spine, 4th joint with 2 successive spines, last joint unarmed and considerably 

 larger than the penultimate, flagellum but slightly tumefied in its proximal part. 

 1st pair of legs very slender and elongated, carpus and propodos extremely nar- 

 row and perfectly smooth ; the 3 succeeding pairs densely clothed with slender 

 spines arranged in a double row ; the 3 posterior pairs of nearly exactly the same 

 structure as in Desmosoma lineare. Uropoda with the inner ramus linear, and 

 about 3 times as long as the basal part, outer ramus not attaining half the length 



