589 



pairs oblong oval in form, with the posterior edge smooth. Last pair of 

 uropoda having the basal part supplied with several small spines, outer 

 ramus conically tapering and tipped with a small spine, inner one somewhat 

 broader and slightly bent in its outer part, which tapers to a point, and 

 has on the upper edge 4 closely set, recurved denticles. Telson but little 

 longer than it is broad at the base, and having, at about the middle on each 

 side, a transverse dorsal row of 4 slender spines: outer part triangularly 

 pointed. Body of somewhat variable colour, now greenish with small black 

 specks, now variegated with light reddish brown transverse bands. Length 

 of adult female 8 mm., of male 9 10 mm. 



Remarks. The present form was first described by Kroyer, in the 

 male sex, from Greenland specimens, as the type of his genus Iscliyrocerus, 

 and was subsequently recorded by Rathke from the west coast of Norway, 

 under another name, viz. Gammarus zebra. Bruzelius referred the species to 

 the genus Podocerus of Leach, and most subsequent authors have followed 

 him in this view. It is chiefly distinguished from the next very nearly 

 related species by its much larger size and by the shape of the posterior 

 gnathopoda in the male. 



Occurrence. - - Off the coast of Finmark this form is rather frequently 

 met with in comparatively shallow water among algae. It also occasionally 

 occurs farther south, as in the Trondhjemsfjord and off the west coast of 

 Norway. Even as far south as Jsedern, I have found it rather plentiful 

 among the red algse. 



Distribution. Arctic Ocean widely distributed : Greenland (Kroyer), 

 Spitsbergen (Goes), Iceland (Torell), the Murman coast (Jarziusky), the White 

 Sea (idem), the Kara Sea (Hansen), the Siberian polar Sea (Stuxberg); Bohus- 

 lan (Bruzelius), Kattegat (Meinert). 



5. Ischyrocerus minutus, Lilljeborg. 



(PI. 210, fig. 1). 

 Ischyrocerus minutus, Lilljeborg, Kgl. Svenska Vet. Acad. Handl. 1850, p. 335. 



Syn : Podocerus anguipes, Boeck (part). 

 > Podocerus isopus, Walker. 



Very like the preceding species, but much smaller. Cephalon with 

 the lateral lobes acutangular. Coxal plates in female comparatively large, 

 in male, as usual, much less deep; 5th pair with the anterior lobe nearly as 

 deep as the preceding pair. Last pair of epimeral plates of metasome rect- 



78 - Crustacea. 



