oirrALiD.is. 115 



cell of considerable size, the latter exceptionally indistinct. 

 Middle tibiae alone provided witli spurs; none of the tibiae 

 ^\•ith an erect bristle before the tip exteriorly. 



The present family includes a large number of species of 

 flies that are sure to be represented in every collection of dip- 

 tera. Many of the species have the wings prettily marked. 

 The family by many entomologists is divided into several 

 independent groups, as the Doryceridaj or Pyrgotinae, the 

 Platystomidae, Ulidiida^,, etc. The flies are usually found 

 about meadows or among luxuriantly growing grass. The 

 larvffi are but pooj-ly known. 



TABLE OF GENEPiA. 



r,Y PROF. W. A. SNOW. 



1. First longitudinal vein beset with small bristles 2 



First longitudinal vein bare 5 



2. Ovipositor flattened ; ocelli present 3 



Ovipositor not flattened; no ocelli. .... Pykgotin;ic. 



o. Third antennal joint round or short ovate; ends of auxiliary and first 



longitudinal veins widely sejiarated. . . 1'tkrocam.in.i<:. 



Third antennal joint not round or short ovate.* .... 4 



4. Neither pro-pleural or sterno-pleural bristles jiresent ; third antennal 



joint elongate rLATYSTOMiN.i;. 



A sternopleural but.no propleural bristle present. . Ckpiialiin.i<:. ,^„ f (<? ' 

 o. Posterior angle of anal cell drawn out into a lobe, or at least, more or i "• 



less acute; femora never armed. ..... Ulidiin^j:. 



Posterior angle of anal cell obtuse, rounded or retracted ; femora armed 

 in most of the genera. ...... PicuAuniiN.*:. 



PYKGOTIN.^. 

 Front strongly projecting; face retreating; oral opening small ; probos- 

 iris not incrassated ; clyi)eus but little developed; ocelli absent; no pro- 

 jjleural bristle; first longitudinal vein hairy; ovipositor not flattened. 



Pyi{<iota Wii'demami. 

 PLATYSTOMlN.l':. 

 Oral oj)ening very large; clypeus generally very much developed, and 

 the proboscis proportionately stout; third antennal joint elongate; nieso- 



* Tetropismenus Loew has the third antennal joint circular, l)Ut its short 

 stigma or subcostal cell locates it among the Ortalina-. 



