of the Families Lopliogastricla3 and Eui)liau.siiJai, 4o7 



aiitoiinulos remarkably broad and flalteiied, Ihtsir 

 inner lla;.'ella small, the outer f,'reat]y developed. 

 Antennal seale limadly trianjrular, breadth subequal 

 to lenr^th ; inner niarfrin ciliated, outer not ciliated, 

 serrated on the edge, serrations four to six. All the 

 legs biramose as in other Schi/.opoda. Telson very 

 large and much longer than the uropods ; extremity 

 narrowly truncate, with a strong spine at each 

 corner, between whieli the termination is serrated 

 and furnished with two setae. Outer uropods one- 

 joiuted L. tijpicits. 



Fam. II. EuphausiidsB. 



All the legs subequal , . . A. 



First legs much longer than the rest B. 



Basal joint of antennules furnished at the extremity with 



an erect, conspicuous, leaf-like appendage Xi/ctiphancs. 



Basal joint of antennules without any erect leaf-like 



appendage at the extremity Boreophuumc. 



B. 



The long first legs having the two terminal joints armed 



with spiniform setfe on both margins Thysanoessa. 



The long first legs gi-eatly produced and very slender, 

 last joints naked (without any lateral setye), the 

 extremity terminating in a bunch of greatly developed 

 porrected spines, these spines serrated Nematoscelis. 



Genus Nyctiphanes. 



A spine on side of carapace behind the middle. Ros- 

 trum nearly obsolete, ocular lobes of carapace pro- 

 duced into spine-like points. No dorsal spine over 

 base of telson N. norveyicu. 



No lateral spines on carapace. Rostrum distinct, shortly 

 triangular, lobes of carapace over eyes not at all 

 produced. A dorsal spine over base of telson .... N. Couchii. 



Genus Boreophausia. 



Rostrum narrow, about as long as first joint of anten- 

 nides ; no spine on the sides of the carapace ; a spine 

 over the base of the telson ; telson longer than 

 lu'opods B. 



