151 



the superior and strongly curved, penultimate joint of the peduncle exhibiting 

 at the end anteriorly a transverse row of slender spines and forming posteriorly 

 a rounded expansion beset with strong plumose setae and a number of curved 

 spines. Antenna 3 in male with the peduncles bearing dense tufts of sensor v 

 hairs, 1st joint of the flagellum of the superior ones very large and densely 

 hairy on the inferior edge, flagellum of the inferior ones not at all differing 

 from that in female, calceolse quite wanting in both pairs. Mandibles with 

 the masticatory part very short, molar expansion extremely small and tipped 

 by 3 slender spines, palp rather narrow and nearly naked except at the 

 obliquely truncated tip. First pair of maxillae with the palp distinctly In- 

 articulate; 2nd pair with the lobes subequal. Maxillipeds about as in the 

 preceding genera, but with the dactylus considerably smaller. Grnathopoda 

 nearly equal-sized, or the posterior ones slightly larger, hands in both pairs 

 oval, with the palmar edge more or less oblique. Antepenultimate pair of 

 pereiopoda with the basal joint linear and not at all expanded; penultimate 

 pair more or less elongated; last pair comparatively small, with the basal 

 joint laminar. Last pair of uropoda in female rather short, outer ramus larger 

 than the inner and spinous ; those in male much more elongated, with both 

 rami knife-shaped and, as a rule, quite naked. Lobes of telson very short 

 and rounded. 



Reiuar/tx. This genus, established by Boeck, is chiefly distinguished 

 by the palp of the 1st pair of maxillae being distinctly biarticulate, and by 

 the narrow linear form of the basal joint of the antepenultimate pair of 

 pereiopoda, The plumose character of most of the setae clothing the antennae 

 and legs, as also the distal edge of the coxal plates, affords another easily 

 recognizable characteristic. Finally, the sexual differences are quite peculiar. 

 The genus is abundantly represented in the northern seas, comprising, as it does, 

 no less than 10 species, to be described in the sequel. Of exotic species only 

 a single form has been described by the Rev. Mr. Stebbing from the Challen- 

 ger Expedition, viz., H. oltusifrons, and another species, H. excnr<if, is recorded 

 by Dr. Chevreux from the bay of (rascogne (Expedition of Hirondelle). 



4. Harpinia plumosa, (Kroyer). 



(PI. 52). 



Phnxus plumoms, Kroyer, Nat. Tidsskr. 1 R. Bd. IV, p. 152. 

 Syn : Phoxus fusiformis ; Stimpson. 



Body moderately compressed and quite glabrous above, with evenly 

 vaulted back. Cephabm somewhat exceeding in length the 3 anterior seg- 

 ments of mesosome combined, hood but slightly projecting beyond the peduncle 



