108 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



In 1897 the above five North American species, including the 

 two new genera, were lumped by Coquillett under the name 

 Myiophasia cenea Wiedemann, and not one of them belongs to 

 that species (Rev. Tach. 50). 



In 1905 Aldrich endorsed Coquillett 's disposition of these five 

 species, stating that he had examined the types and verified the 

 synonymy in each case, and commented on what he considered 

 the description of the same species "several times under different 

 genera, or in the same genus," intimating the folly of attempting 

 to draw descriptions too closely in these flies and pointing out this 

 as the worst example of the kind committed by the present writer 

 (Cat. Dipt. N. A. 420, 421 and 427). Such is the history in brief 

 relating to the celebrated case* of Myiophasia cenea. 



The writer implied in 1908 that the last word had not yet been 

 said on this case, stating that several well-marked forms have 

 been confused here, and described a sixth new North American 

 species of the group under the name Myiophasia setigera (Tax. 

 Muse. Flies 56). He has now completed a study of the external 

 adult characters of all the forms of the Myiophasia group repre- 

 sented by material in the U. S. National Museum collection, 

 comprising 164 specimens. The results of this study are the 

 selection of Lcewia globosa and Lcewia nigrifrons to serve as geno- 

 types of the two new genera Eulcewia and Ennyommopsis re- 

 spectively, and the validation of both Phasiodista and Ennyomma 

 and their genotypes. While the genus Myiophasia can not be 

 positively determined in the absence of material from Monte- 

 video, it appears probable that the above species setigera from 

 western North America may belong to it, and the species is pro- 

 visionally referred thereto. 



The following synoptic table will serve to separate the five 

 genera and various subgenera, species and subspecies of this group, 

 which forms a natural tribe on the borderline between the Dexiinse 

 and Megaprosopinse. Every one of the 164 specimens in the 

 U. S. National Museum collection can be quite readily deter- 

 mined by it with the exercise of a little care. 



SYNOPSIS OF NORTH AMERICAN MYIOPHASIINI. 



1. Apical cell ending in or very close to exact wingtip, normally closed; 

 axis of hind crossvein strongly oblique to that of apical crossvein, 

 in middle between small crossvein and bend of fourth vein or nearer 

 to former; eyes of male normally thickly pubescent, those of female 

 very thinly and inconspicuously so but the hairs always visible. . . .2 

 Apical cell ending conspicuously before exact wingtip, usually open; 

 axis of hind crossvein nearly or quite parallel with that of apical 

 crossvein 4 



