146 NORTH AMERICAN DIPTERA 



Family Coenomyiidae 



Flies of medium to large size, the antenna elongate, with the third 

 segment annulate and more or less clearly subdivided. 



Males holoptic or dichoptie. Antennae never with a distinctly dif- 

 ferentiated style although the terminal annulus may resemble one to a 

 certain extent. Empodium developed pulvilliform, the pulvilli present. 

 Squamae small. Wing venation w^ell developed, the discal cell always 

 present, the fourth posterior cell sometimes closed. 



As here defined this family includes insects of diverse structure but 

 there seems to be no good character for their separation. The genus Coe- 

 nomyia has been placed in various families, including the Rhagionidas, 

 Tabanidas and Stratiomyidse. It appears, however, because of the facial 

 structure, to be best placed between the two last mentioned families. 

 Upon general structure alone Cocnonujia might well be isolated from the 

 remainder of the other included genera except tliat Ariliropms magnus 

 Johnson is very similar in appearance, differing only in having bare 

 eyes and in lacking the scutellar spines. 



The adults are found in woods, especially near moist places, while 

 the larva? mostly occur in decaying wood, under the bark of trees or in 

 the soil and are carnivorous and predaceous. The opinion has been 

 expressed that the larvge of Canoynyia may live upon the immature 

 stages of Cicadas. A revision of the North American species will be 

 found in Leonard* "Revision of the Rhagionidte in the United States 

 and Canada." 



I might add that I cannot agree that the genus Solva Walker 

 belongs to the Stratiomyidae although there is no doubt that there is 

 some relationship. Both the facial shape and wing venation exclude 

 it from that family. 



KEY TO GENERA 



1. Eyes bare 2 



Eyes pilose (9, 11) Coenomyia Latreille 



2. Anterior tibiae with one terminal spur 3 



Anterior tibiae without terminal spur 4 



3. Antennee acute at the tip, the apical annulus elongate (1, 8). 



Arthropeas Loew 

 Antennae obtu.'^e at the tip, the apical annulus short and broad (3, 7). 



fXylophagus Meigen 



4. Fourth posterior cell open 5 



Fourth posterior cell closed (5, 12) Solva Walker 



5. Face with a very large, prominent pilose swelling on either side (2, 10). 



Glutops Burgess 

 Face not strongly swollen laterally, bare (4, 6) Arthroceras Williston 



* 1930. Mem. Amer. Ent. Soc, No. 7. 



t Cui-ran. 1933, Amer. Mus. Novitates No. 673, p. 1. 



