346 



Distrihution. — 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, Bmzelius, 1859 

 Syn. ; Pleustes, Boeck (part.). 



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

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

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

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

 plates com])aratively 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 oblif^ue 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, spiniforra. Gnathopoda, as a rule, far less powerful than in the above 

 genus, and somewhat diffei'ing in structure in the diiferent sjiecies. Perei- 

 opoda more or less elongated. Last j^air of urojjoda of a similar structure 

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

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

 keel along the lower face. 



Uemarl;s. — In the restriction here adopted, this genus is chiefly 

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

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

 less powerful structure of the gnathopoda, 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 hrst time e.stablished. — 



2. Paramphithoe pulchella (Kroyer). 



(PI. 122, fig. 1.). 



AmjMthoc puldiella, Kruyer, Gaimard's Voyage en Seaiidinavie, Zoologie, PI. 10, fig, 2. 



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



Body very slender, and somewhat compressed, with the 3 postei'ior 

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

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



