__JL47_ 

 2. Leptophoxus falcatus, G. 0. Sars. 



(PI. 50). 



Phoxus falcatus, G. O. Sars, Oversigt af Norges Crustaceer I. \>. 84. 

 Syn : Phoxus simplex, Boeck (not Sp. Bate). 



Body very slender and compressed, especially in the male, Cephal<m 

 exceeding the length of the 3 anterior segments of mesosome combined, lim.d 

 distinctly carinated along the middle and terminating with a hook-like deflexed 

 point, The 3 anterior pairs of coxal plates each with 3 small bristles at tin- 

 infero-posteal corner; 1st pair considerably expanded in their outer part, distal 

 edge arched; the 2 succeeding ones regularly quadrangular; 4th pair mudi 

 broader than the preceding ones, and transversely truncated posteriorly, upper 

 angle nearly right; 5th pair with the posterior lobe slightly expanded and 

 obtusely truncated at the tip, upper angle rather projecting. Last pair <>!' 

 epimeral plates of metasome with the posterior edge considerably arched, 

 lateral corners obtuse. Eyes wholly absent. Superior antennae much shorter 

 than the cephalon, 1st joint of the peduncle rather thick and considerably 

 exceeding the length of the other 2 combined, flagellum about the length of 

 the peduncle, and composed of 5 articulations, accessory appendage scarcely 

 half the length of the flagellum, and 3-articulate. Inferior antennae in female 

 nearly twice the length of the superior and more or less strongly curved, 

 the 2 outer joints of the peduncle armed anteriorly with tufts of slender 

 spines, and posteriorly with a few ciliated setse, fiagellum scarcely half the 

 length of the peduncle, and 5-articulate ; those of male not fully attaining the 

 length of the body. Penultimate joint of the palp of the maxillipeds pro- 

 duced at the outer corner to a narrow conical process tipped with 4 ciliated 

 setse. Gnathopoda rather powerful, hand of the anterior ones narrow quadnin- 

 gular, that of the posterior nearly twice as large, and subquadrate in form, 

 thumb-like process in both rather projecting. Antepenultimate pair of pereiopoda 

 with the basal joint fully as broad as it is long, posterior edge evenly arched; 

 penultimate pair nearly attaining half the length of the body ; last pair with 

 the basal joint rather large, though not attaining the length of the remaining 

 part of the leg, posterior edge obliquely arched, and exhibiting a few slight 

 serrations. The first 2 pairs of uropoda with both rami slender, mucroniform 

 and quite naked; last pair projecting considerably beyond the preceding ones, 

 inner ramus extremely small, the outer slender, with the terminal joint very 

 narrow and about half the length of the basal one. Telson slightly dilated 

 in the middle, each lobe tipped with a single spine and a small bristle. 

 Body whitish, pellucid. Length of adult female 4mm; of male about the same. 



Remarks. - The present easily recognizable form, wliirli was errone- 

 ously identified by Boeck with Phoxus simjile.r Sp. Bate, is at oner distinguished 



