April, 1917 Bulletin of the Brooklyn Entomological Society 35 



Herrick-Schaeffer described under the name of albicostaria a 

 species from the West Indies, which for a long while I considered 

 might be the same with this, but a close study of a specimen, 

 which I think should bear his name, taken by the late J. A. Gross- 

 beck at Curacoa, and others from Porto Rico through the kind- 

 ness of Geo. B. Engelhardt, leads me to believe them quite dis- 

 tinct. Later, it may be possible to confirm this opinion by com- 

 parison of genitalic mounts. 



A KEY TO THE NORTH AMERICAN GENERA OF 

 CCENOSIIN^ (DIPTERA, ANTHOMYIID^). 



By J. R. Malloch, Urbana, 111. 



The members of this subfamily maybe distinguished from other 

 anthomyiids by the following combination of characters : 



Under-surface of scutellum bare; sternopleural bristles 3 in 

 number, arranged almost invariably in a nearly equilateral tri- 

 angle, if 4 are present the additional one is ventrad of the lower 

 posterior one ; hypopleura and pteropleura bare ; anterior supra- 

 alar bristle absent or very minute ; eyes of both sexes separated by 

 about one third the width of head ; frontal cruciate bristles ab- 

 sent; sixth vein of wing usually incomplete, complete only in 

 Neochirosia. 



The early stages are but poorly represented in my material — 

 the only 2 species I have reared being found in the larval stage 

 under bark of fallen trees and in rotten wood. 



The imagines of most, if not all, of the species are predaceous, 

 feeding upon minute insects such as Chironomidae, Sciaridae, etc. 



Key to Genera. 



1. Sixth vein of wing extending to margin Neochirosia. 



— . Sixth vein of wing discontinued considerably before margin 2. 



2. Frons much broader than long, distinctly narrowed anteriorly, inner 



margin of eye concave above, the width of either eye viewed from 



above not' greater than half the width of frons . . Schoenomysa. 



— . Frons at least as long as broad, usually very much longer, width of 

 eye about equal to that of frons 3- 



