230 NORTH AMERICAN ANTHOMYIID FLIES OF GENUS PHAONIA 



Dipterists who have carefully studied the legs of the species 

 realize that there are more than four surfaces to the tibiae. 

 Ordinarily one finds but four in descriptions of Muscaridae, 

 upper, under, inner, and outer. These correspond, at least on 

 the mid and hind legs, to those designated in my papers as dorsal, 

 ventral, posterior, and anterior respectively. There are as a 

 matter of fact very few strong bristles found on any of the four 

 surfaces mentioned except at apices of the tibiae, the outstanding 

 bristles being almost invariably situated on the other four sur- 

 faces which are between those listed and are termed the antero- 

 ventral, anterodorsal, posteroventral, and posterodorsal. The 

 names are self explanatory. 



A close examination of the hind tibia of Phaonia errans Meigen 

 shows that the "calcar" so called is situated less than one-third 

 of the tibial length from apex and on the posterodorsal surface, 

 there are two bristles on the anterodorsal surface, and two or 

 more on the anteroventral. The setulae on the median portions 

 of the anterior and posterior surfaces are rather strong, but the 

 dorsal and ventral surfaces are devoid of bristles or outstanding 

 setulae. The names used in designating the surfaces of the 

 tibiae apply also to the femora. 



The thoracic chaetotaxy and the names applied to the bristles, 

 and the regions where they are situated, are used in any book 

 or paper on the Cyclorrhapha, are familiar to students the 

 world over and require no elucidation except in a few cases. 

 Recent attempts to separate the Muscaridae from the Anthomyi- 

 idae have not been entirely satisfactory, and in my opinion there 

 are so many overlapping groups, genera, and species that it 

 cannot be done, at least for the world's fauna. The most recent 

 characters cited give to the Muscaridae (Muscidae auct.) hairs 

 on either the hypopleura or pteropleura or both, while the An- 

 thomyiidae have those sclerites bare. As a matter of fact there 

 are many species that are very obviously anthomyiine in their 

 affinities, which have hairs on either or both of the pleural 

 sclerites, referred to not only in Phaoniinac, which are in my 

 opinion most closely allied to the group containing Musca, but 

 also in the Anthomyiinae. I have no hesitation in linking the 

 two groups under the same family name, Muscaridae. 



