48 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



DD. Peduncular joints of antenna I not produced distally 



An onyx. 



AA. Without tliis combination of characters. 

 B. Eyes simple, usually 4 (Ampeliscidae). 



C. Uropod 3 extending much beyond the others, telson ob- 

 long and deeply cleft Ampelisca p. 61 



CC. Uropod 3 not extending much beyond the others, telson 



short and not deeply cleft Byblis p. 67 



BB. Eyes usually present, never more than one pair and never 

 simple. 



C. Pereiopods without dactyls Haustorius p. 70 



CC. Pereiopods with dactyls. 

 D. Rostrum produced into a hood over the antennae; pereio- 

 pod 4 much longer than last pair (Phoxocephalidae). 



E. Eyes wanting Harpinia. 



EE. Eyes small Phoxocephalus p. Ti 



EEE. Eyes large Paraphoxus p. 75 



DD. Rostrum not as above. 



E. Coxal plate 4 greatly enlarged to form large lateral 

 shield. 



F. Uropod 3 biramous Stegocephalus p. 60 



FF. Uropod 3 uniramous. 



G. Mandibular palp small, 3-jointed Metopa. 



GG. Mandibular palp wanting Stenothoe p. 78 



EE. Coxal plate 4 not greatly enlarged. 



F. Body depressed, rostrum large, broad not acute; no 

 accessory fiagellum; mandibular palp large; 

 gnathopod I simpje; gnathopod 2 weakly sub- 



chtlate Lafystius. 



FF. Without this combination of characters. 



G. Last pereiopod the longest, dactyl styliform; eyes 



nearly contiguous above Monoculodes p. 83 



GG. Dactyl of last pereiopod not styliform. 



H. Gnathopod t rudimentary Batea p. 89 



HH. Gnathopod i not rudimentary. 



I. Pereiopods I and 2 without spinning glands«. 

 J. Antenna I with calceoli. 



K. Last joint of peduncle of antenna i pro- 

 duced to form a triangular process.. 



Calliopius p. 86 

 KK. Last joint of peduncle of antenna i not 



so produced Pontogeneia p. 91 



JJ. Antenna i without calceoli. 



K. Mandible with palp; uropods 2 and 3 not 

 enormously developed. 

 L. Thoracic segments strongly tubercu- 



lated Epimeria. 



