332 NEW YORK STATE MUSEUM 



Convex, oval; breathing tubes composed 

 of several lamellae Blepharoceridae 



7 Prothoracic respiratory appendages sim- 



ple, slender, antennaelike; pupa slug- 

 gish or motionless (8) 



Prothoracic appendages short and pointed, 

 or club shaped, or composed of numer- 

 ous fine filaments, or entirely want- 

 ing (9) 



8 First abdominal segment about as long as 



those following it . , Some Psychodidae 



First abdominal segment about half as 



long as those following it Tipulidae 



9 Prothoracic appendages short and pointed R h y p h i d a e 



These appendages not as above (10) 



10 With two rounded paddlelilie appendages 



at the caudal end.i Pupa active Culicidae 



Without distinct paddles (if present, then 

 pointed, and with ciliate margin). . .(11) 



11 The caudal end with two pointed pro- 



cesses and usually bent forward over 



the pectus; the pupa resting on its side DixTdae 



Prothoracic appendages either many 

 branched, simple or apparently want- 

 ing, the pupa in the larval tube (Chi- 

 ronomus) or active, Culexlike (Tany- 

 pus); or floating nearly motionless 

 (Ceratopogon) Chironomidae- 



The above keys are modifications of those given by Mr C. A. Hart, 

 Illinois State Lab. Nat. Hist. Bui. 1895. v.4, art.6, p.186-89. 



To determine the imagines, the reader is referred to Comstock's Manual 

 for the Study of Insects, or to Williston's Manual of the North American 

 Diptera. 



Family bleph.a.roceridae: 



'Net-icinged midges 

 These flies are of moderate size, elongate and bare, with long^ 

 legs and broad wings. The ocelli are present; the proboscis is 

 elongated; the antennae are slender, composed of from six to 

 16 joints, clothed with short pubescence. The thorax has a 

 distinct though interrupted suture. The empodium is verj 

 small and the pulvilli are wanting. The wings are broad, with- 

 out hair, with a projecting anal angle; characterized by a net- 

 work of fine lines which extend in various directions and not 



iCorethrella (q. v.) is an exception: having two pointed caudal lobes. 



