118 NORTH AMERICAN DIPTKRA. 



2. Wings very narrow in proportion to their length, of equal width, broad- 



ly rounded at base and tip. . . . PTEROCALLA Hondani. 



Wings witli an unusually convex posterior margin. CALLOPISTRIA Loew. 



8. Anterior and posterior cross-veins very oblique, not approximated 



(Mexico). . . . , . . . MTKNNIS Desvoidy. 



Posterior cross-vein rectangular or nearly so ...... 4 



4. Second longitudinal vein straight or nearly so ; anterior cross-vein not 



oblique. . . ... . -. ..... & 



Second longitudinal vein markedly sinuous ; cross- veins approximated 

 and the anterior one very oblique.* PARAGORGOPIS Giglio-Tos. 



5. Cheeks rather broad; posterior angle of anal cell acute. 



STICTOCEPHALA Loew. 



Cheeks and face extremely short ; eyes transversely oval ; posterior 

 angle of anal cell rectangular (New Mexico). PSAIROPTEKA Loew. 



Head large, hemispherical; proboscis stout, with broad labella; front 

 broad; antennae short; mesonotum bristly in the middle behind only; first 

 and third longitudinal veins of the wings bare, the third and fourth con- 

 vergent distally ; posterior angle of the anal cell acute, sometimes drawn 

 out into a long lobe. 



1. Head conspicuously large ; front unusually broad and the antennae very 



widely separated. . . . , . " . . . . 2 



Head not conspicuously large, the antennae more approximated at their 



root. ........... 3 



2. Third antennal joint round ; front punctulate. . . CEwiPA Loew. 

 Third antennal joint elongate; upper part of front rugose. 



KURYCKPHALA Boeder. 



3. Posterior angle of anal cell acute, but scarcely prolonged lobe-like. 8 

 Posterior angle of anal cell distinctly drawn out into a lobe. . 4 



4. Front punctate or scrobiculate. . . ... . . . & 



Front smooth, . . ...... 7 



6. Scutellum flat, with sharp edges; fourth longitudinal vein strongly 

 curved forward at its end ; front coarsely rugose. 



NOTOGRAMMA Loew. 



Scutellum convex, rounded on its edges. 



(>. Stigma not unusually elongate. . . '. . . ULIDIA Meigen. 

 Stigma elongate, about as long as the costal cell. ACROSTICTA Loew. 



* This genus is located here as definitely as the characters given will 

 permit. 



