ORTALID.T:. 117 



2. Wings dark, with three oblique, more or less arcuated, hyaline cross- 

 bands ; first basal cell expanded before its end. TRITOXA Loew. 

 Wings not with such markings. ....... 3 



.'I. Wings broad, with a marked excision on the costa near the end of the 



auxiliary vein; secoud vein sinuous. OAMPTOXEI-RA Mat-quart. 



Flies not having such wings . . 4 



4. Posterior angle of the anal cell retracted. . . . IDAXA Loew. 

 Posterior angle of the anal cell drawn out into a long lobe. 



DIAORITA Gerstaecker. 



ORTALIXJE. 



The Ortalinae differ from the Platystominae and Cephailinae in the small 

 oral opening, the less developed clypeus, more slender proboscis and smaller 

 palpi. The mesonotum is sometimes bristly in the middle anteriorly, the 

 propleural and mesopleural bristles both present. Female abdomen with 

 six segments. 



1. Face sharply carinate. . . . .'"... ".- - 

 Face not sharply carinate. . . ."'.-. . . . . :-) 



2. Third antennal joint circular; hairy species. TETROPISMEXUS Loew. 

 Third antennal joint ending in a sharp point; pollinose flies. 



TEPHROXOTA Loew. 



8. Mesonotum bristly in the middle in front; third antennal joint excised 

 above and with a pointed tip. . . , CEROXYS Mat-quart. 



Mesonotum not bristly in the middle in front 4 



4. Third antennal joint distinctly excised above, pointed at the tip ; fourth 

 longitudinal vein with a marked anterior curvature on its distal 



part ; AXACAMPTA Loew. 



Third antennal joint not excised above; fourth vein not so curved; 

 body nearly destitute of bristles or hairs. . TKTAXOPS Fallen. 



PTEBOCALLIXjE. 



Trypeta-like; coloring non metallic ; head rather broad, but low, with 

 rather protuberant eyes; face short, perpendicular, excavated in the mid- 

 dle; clypeus but little developed ; third antennal joint round or short oval ; 

 mesonotum bristly upon the posterior part only; third longitudinal vein 

 hairy ; tip of the first longitudinal vein and auxiliary vein remote from 

 each other; posterior angle of the anal cell usually drawn out into a long 

 lobe. 



1. Posterior angle of anal cell drawn out into a long lobe ; posterior cross- 

 vein very oblique. . . . . . . -. . . 2 



Posterior angle of anal cell not greatly produced. . * . .. . ! 



