346 



Distribution. - Arctic Ocean, widely distributed ; Greenland (Kroyer), 

 Atlantic coast of North America (Packard), Labrador (Smith), Spitsbergen 

 (Goes), Iceland (Torell), the Murman Coast (Jarzynsky), the Kara Sea 

 (Hansen), the Siberian Polar Sea (Stuxberg). 



Gen. 2. Paramphithoe, Bruzelius, 1859 

 Syn. : Pleustes, Boeck (part.). 



Body, as a rule, much more slender than in the preceding genus and 

 having the integuments far less strongly incrusted. Cephalon more or less 

 produced in front, above the base of the superior antennae, postantennal corn- 

 ers generally exserted to an acute, anteriorly-curving projection. Coxal 

 plates comparatively smaller than in Pleustes. Superior antennae in most of 

 the species very slender and elongated, and much longer than the inferior 

 ones. Anterior lip somewhat unequally bilobed, having in the middle a 

 narrow oblique incision. Mandibles with the molar expansion imperfectly deve- 

 loped, palp exceedingly large, with the last joint falciform curved. Maxillse 

 nearly as in the preceding genus. Maxillipeds with the palp comparatively 

 more slender, and having the last joint attenuated distally, dactylus nearly 

 straight, spiniform. Gnathopoda, as a rule, far less powerful than in the above 

 genus, and somewhat differing in structure in the different species. Perei- 

 opoda more or less elongated. Last pair of uropoda of a similar structure 

 to those in Pleustes, though generally more slender. Telson comparatively 

 small and navicular in form, being deeply hollowed above, with a projecting 

 keel along the lower face. 



Remarks. In the restriction here adopted, this genus is chiefly 

 distinguished from the preceding one by the far less robust form of the body, 

 the thin and pellucid integuments, the large size of the mandibular palp, the 

 less powerful structure of the gnathopocla, and finally by the peculiar form 

 of the telson. It comprises 6 northern species (to be described in the sequel), 

 one of which is now for the first time established. - 



2. Paramphithoe pulchella (Kroyer). 



(P). 122, fig. 1.)- 



Amphitlioe pulcliella, Kroyer, Gaimard's Voyage en Scandinavie, Zoologie, PI. 10, fig, 2. 

 Syn.: Pleustes pulchellus, Boeck (the discription, but not the figures). 



Body very slender, and somewhat compressed, with the 3 posterior 

 -foments of mesosome (also more rarely one or more of the preceding ones) 

 and the first 2 segments of metasome produced dorsally to compressed, poste- 



