44 DIPTERA OF NORTH AMERICA. 



FAM. LI. DIOPSIDAE. 



Charact. Neuration of the wings incomplete from the absence of the 

 foremost of the two small basal cells ; the auxiliary vein very much 

 approximated to the first longitudinal vein. Head prolonged in 

 two lateral apophyses bearing the eyes ; front bristly only on the 

 upper part ; border of the mouth with no vibrissaB. Anterior femora 

 incrassated. 



One species, or if the second one, described by Dr. A. Fitch, 

 should really prove different two species of the genus SPHYRACE- 

 PHALA Say have hitherto been found in N. A. 



FAM. LII. PIOPHILIDAE. 



Charact. The auxiliary vein, on its whole length, is coalescent with the 

 first longitudinal vein ; with this exception the neuration of the 

 wings is complete. Front with some small bristles above only ; bor- 

 der of the mouth with a vibrissa on each side ; clypeus rudimentary; 

 legs rather stoat, almost of the structure of those of the Sciomyzidce; 

 middle tibiae with spurs ; all the tibiae without erect bristle on the 

 exterior side before the tip. 



The three N. A. species of PIOPHILA which I have seen are quite 

 identical with European ones; a fourth differs so much from all the 

 known Piophilce in the form of the head and the structure of the 

 antennae, that it must be considered as the type of a new genus. 

 It seems to be the same species on which Mr. Walker has founded 

 his genus PROCHYLIZA; if that be really so, he would, by assigning 

 it a place immediately by Chyliza, have shown that he had been 

 fully mistaken about its true relation. 



FAM. LIIL EPHYDRINIDAE. 



Charact. Face convex, with no distinct furrows for the reception of the 

 antenna? and without vibrissse, though frequently beset with hairs or 

 bristles; clypeus very much developed ; opening of the mouth large ; 

 proboscis incrassated with a swollen chin. Neuration of the wings 

 incomplete ; the auxiliary vein distinct only at its base ; the fore- 

 most of the two small basal cells reunited with the discal cell. 

 Middle tibise with spurs. 



They are divided into three sections : Notiphilina, Hydrellina, 

 and Ephydrina. The Notiphilina are characterized by the second 



