16 Families and Genkha of 



FAMILY CHARACTERS AND SYNOPSES OF GENERA. 



NOT A CANT H A. 



Empodia developed pulvilliforni, pulvilli present. Without dis- 

 tinct bristles. Basal cells of wings large. Third joint of antennae 

 segmented or annulated. Tegiilaj small or rudimentary. Proboscis 

 not adapted for piercing. Males holoptic or dichoptic. 



1. Tibiae wholly without spurs ; veins usually crowded anteriorly. 



Stratiomyida; 



Tibiae more or less spurred ; the costal vein encompasses the 



whole wing ; two sub-marginal and five posterior cells always 



present .2 



2. All the tibiae with spurs. ........ 3 



Front tibi:e without spurs. ....... 4 



3. Third joint of antcnnie not acute at tip, or, if so, the scutellum 



with spines on its border. . . . Xylophagid/E 

 Third joint acute; palpi cylindrical; scutellum without spines. 



Arthropeas 



4. Fourth posterior cell closed. ..... Subcla 



Fourth posterior cell open. (Leptidae.) .... 5 



5. Face projecting on each side into a rounded conical protuberance, 



thickly covered with hair. ..... Glutops 



Face with two deep, diverging furrows, running from the base of 

 the antenna; to the oral margin. . . Arthroceras 



XYLOPHAGID^. 



Species of moderate or large size, more or less elongated, thinly 

 pilose, or nearly bare. Ocelli present. Antennie elongate, third 

 joint annulated or segmentated, never with a differentiated style or 

 bristle. Veins of the wings distinct, not crowded anteriorly, third 

 longitudinal vein furcate; five j)osterior cells. Abdomen with seven 

 or eight visible segments. All the tibiae with spurs at the tip. 



The flies are usually found about trees, where they feed upon the 

 sap, or about decaying logs, and are often mistaken for iclineu- 

 monids. 



