J. R. MALLOCH 239 



PHAONIA Robineau-Desvoidy 



This genus as now limited contains species which have a strong 

 bristle beyond middle on posterodorsal surface of hind tibia; 

 the fourth wing-vein not or almost imperceptibly bent forward 

 apically; third vein not setulose at base, or rarely so on under 

 surface only; pteropleura bare; prosternum bare; cheek with or 

 without fine hairs, or setulose above lower margin, never with 

 one or two strong bristles below anterior margin of eye and near 

 or on lower margin of cheek; female never with the lower supra- 

 orbital bristle strong and forwardly directed; thorax with two 

 strong presutural dorsocentrals. 



Genotype, Musca erratica Fallen. 



As previously stated and exemplified in the key to genera and 

 subgenera in this paper, there are several groups in this genus, 

 most of which are segregated in the following key to species. 

 But there are many intermediate forms which cannot be de- 

 finitely placed in any of the larger groups, so rather than add to 

 the difficulty in identifying these by creating a multiplicity of 

 genera based on a variable number of characters, I have followed 

 the course of leaving them all in one composite genus until such 

 time as our knowledge of the species and their habits warrants 

 a further segregation. Should it be deemed necessary at any 

 future time to erect genera for any of these segregates, con- 

 sideration will have to be given to the genera proposed by the 

 older European authors, which are at this time listed as synonyms 

 of Phaonia. 



Key to Species 



1. Hypopleura with some fine hairs on upper margin in front of spiracle; 



eyes usually with distinct hairs 2 



— Hypopleura bare on upper margin in front of spiracle 30 



2. Legs entirely black, only the knees more or less reddish, sometimes the 



hind tibiae reddish when held up to the light 3 



— Legs with at least the tibiae reddish 3'ellow IG 



3. Thorax with one or more pairs of strong outstanding presutural acro- 



stichal bristles 4 



— Thorax without strong outstanding presutural acrostichal bri.stles, with 



fine hairs only 10 



4. Fore tibia without any strong posterior median bristles 5 



— Fore tibia with one or more strong median posterior bristles S 



TRANS. AM. ENT. SOC, XLVIII. 



