328 



NORTH AMERICAN DIPTERA 



Family Asteiidae 



Small flies, with the second vein ending only slightly beyond the 

 first. 



Head higher than long; face concave; oral viln'issse well developed; 

 front wide, wath one or two pairs of bristles; thorax bristled posteriorly. 

 Legs short. Wings long, with only one or two crossveins, before the 

 basal third; auxiliary vein incomplete; costa entire, anal cell absent, 

 the second basal sometimes open apically. Abdomen narrow. 



This family comprises but few genera, three of which are recorded 

 from America. The family may be at once recognized by the peculiar 

 wing venation. Williston placed the two genera known to him in both 

 the Drosophilidie and Chloropidt^ and there has been much doubt as to 

 where they belong. 



KEY TO GENERA 



1, Posterior crossvein present 2 



Posterior crossvein absent, only one crossvein (3) *Asteia Meigen 



2. Front with two bristles near the middle, half way between the ocellar 



triangle and antennse Crepidohamma Enderlein 



Front with only weak bristles laterally (1, 2) . Sigaloessa Coquillett 



* Aldrich, 1915, Psyche, xxii, p. 96. 



Asteiidse. — 1, 2, Sigaloessa rica (insularis Curran, not Malloch) ; 3, Asteia sp. 



