188 Illinois State Laboratory of Natitral History. 



Stigmatal cleft transverse, head not retractile. [Fig. 



58.] (Soldier-flies.) StratiomyiidcB. 



Posterior stigmatal tubes or plates separated. (This 

 includes all the remaining orthorhaphous families, 

 of which but one genus belonging to the following 

 family has been reported as aquatic.) 

 Head long, pear-shaped, retractile, ventral profile 

 straight; 11-12 body segments; posterior stig- 

 mata on last segment. (Snipe-flies.) LeptidoB. 



Ortfiorapha — Pupce. 



Prothoracic spiracles borne upon appendages. {H'em- 

 atocera. ) 



Not in a cocoon, sometimes in the old larval tube. 

 Prothoracic respiratory appendages simple, slender* 

 antenna-like. 

 Body subcylindrical. 

 First abdominal segment about as long as those 

 following it; each pair of tarsi separately in 

 contact, overlapping the pair next behind it. 



PsychodidcB. 

 First abdominal about one half as long as those 

 following it. 

 Prothoracic appendages symmetrically devel- 

 oped [Fig. 31]; tarsi all in one group, side 



by side and not overlapping TipuUdcB. 



Prothoracic appendages very unequal in length- 

 [Fig. 19] ; anterior tarsi in contact, over- 

 lapping middle pair Ptychopteridw, 



Body convex, oval, hard-shelled above. 



BlepharoccridcB. 

 Prothoracic appendages simple but not filiform, some- 

 times compound. 

 These appendages more or less clavate. 

 Last segment large, ending merely in two pointed 

 prolongations; prothoracic appendages short. 



Dixidod, 



