156 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



that I feel they should be recognized m siibgeneric catagories. Even- 

 tually most of them will prove to be of generic importance; buti 

 until a worldwide study is made, and until the family is better known, , 

 it is better to retain the present level of generic division. 



Acknowledgment is made to the following individuals and institu- 

 tions for the loan of specimens, information on types, and other 

 assistance and advice. Without their generosity this work could I 

 not have been accomplished. 



C. W. Sabrosky, U. S. Department of Agriculture; H. Oldroyd, 

 British Afuseum (Natural History) (BM); C. H. Curran, American! 

 Museum of Natural History (AMNH); S. L. Tuxen, Universitetl 

 Zoologiske Museum, Copenhagen (UZM); H. Mayer, Naturhis- 

 torisches Museiun, Vienna (NMV); E. Seguy, Museum National 

 d'Histoire Naturelle, Paris (M^HNP); P. J. Darlington, Jr., Museum 

 of Comparative Zoology (MCZ); R. H. Beamer and J. Hall, Snowj 

 Museum, University of Kansas; P. D. Hard, Jr., University of Cali- 

 fornia, Berkeley (UCB); and H. Dybas, E. Ray, and R. Wenzel, 

 Chicago Natural History Museum (CNHM). 



Key to genera of New World Conopinae 



1. Face not grooved, sharply keeled Tropidomyia Williston 



Face with grooves, separated by a shallow keel 2J 



2. Cheeks wide, equal to one-half eye-height . . . Mallochoconops, new genusi 

 Cheeks much narrower than one-half eye-height 3S 



3. Posterior femur thickened and angulated at base; anterior cross-vein muchlj 



beyond middle of discal cell Physocepliala Schiner] 



Posterior femur normal; anterior cross-vein near middle of discal cell ... 4 



4. Vertex with distinct ocellar swelling; second abdominal segment, especially int 



male, relatively long and narrow Physoconops Sziladyj 



Verte.x without ocellar swelling; second abdominal segment short and wide. 



Conops Linn6 



Genus Conops Linne 



Conops Linn4, Systema naturae, ed. 10, p. 604, 1758. 



Most of the species formerly placed here belong to Physoconops, \ 

 which is much more common that Conops in the New World. 



Information on the types of the following species indicates that they; 

 belong to Physocephala. 



Conops cayennensis Macquart, Dipteres exotiques, vol. 2, suppl. 3, p. 12, 1843^ 



Cayenne. (Type in MHNP.) 

 Conops flavifrons Walker, List of the specimens of dipterous insects in the 



collection of the British Museum, vol. 3, p. 672, 1849. Pard. (Type not 



found.) 

 Conops aurifrons Walker, List of the specimens of dipterous insects in thet 



collection of the British Museum, vol. 4, p. 1158, 1849. (Type in BM. A 



synonym of C. flavifrons.) 



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