463 

 Wirth and Stone: Diptera 



Fig. 14:54. Ephydr idae. o-c, Scatella stagnalis (Fall.), larva: a, anterior segments with pharyn- 

 geal skeleton; c, posterior spiracle; fa, puparium. c/,e, Atissa litoralis Cole, adult: d, lateral view; 

 e, head, anterior view, f, L/pocfaoefa sfossonae Coq., adult; g, Neoscafe//a oofauensis (Will.), 

 head; fa, Notiphila virgata Coq., adult, head; i-fc, Paralimna punctipennis (Wied.), adult: i, antenna; 

 /', wing; k, head (o-c, Tuxen, 1944; d-f, Cole, 1912; g, Wirth, 1948; fa, Cresson, 1917; l-k, Cresson, 

 1916). 



Keys to the North American Genera of Ephydridae 



Adults 



1. Median facial area setulose, the facial series of 

 bristles converging above; mouth opening large and 



cavernous, its margin often ciliate with long bristles 

 (fig. 14:54<7); presutural dorsocentral bristles present 



and well developed (EPIIYDRINAE) 49 



Median facial area bare, the facial bristles in more or 

 less vertical series, parallel with the orbits (figs. 

 14:54e, 14:55a, d,f-m); presutural dorsocentrals present 



