16 DIPTERA OF NORTH AMERICA. [PART III. 



the genera which we are considering under the general name of 

 Phytomydse Myodinae. This generalization may be considered 

 as successful, as it contains but little which is foreign, that is 

 which would be better placed among his Aciphoreae, equivalent 

 to the family Trypetidee, and as at the same time it excludes 

 but little of what really belongs to the Ortalidae. The position 

 also which Rob. Desvoidy assigns to the Phytomydse Myodinae, 

 next to the Phytomydae Thelidomydae, that is, the Micropezidas, 

 cannot but be sustained, as the latter are closely related to the 

 Ortalidae. After his Phytomydae TJielidomydas Rob. Desvoidy 

 places his Aciphoreae, that is, the Trypetidae, while he would have 

 done better in reversing this order of his two divisions, on ac- 

 count of the close relationship between the Ortalidae and the 

 Trypetidae. The sovereign neglect- of all previous publications, 

 the wretched manner in which most of his genera are established, 

 chiefly upon merely relative differences (for instance, a some- 

 what longer third antennal joint, a somewhat more pubescent 

 arista, etc.), without regard to the most striking plastic cha- 

 racters, the very slovenly description of many species of un- 

 known habitat, etc., have, long ago, put this author's writings in 

 such bad repute that it would not be easy to add anything to 

 it. It would be unjust, however, after this fully deserved blame, 

 not to recognize that Rob. Desvoidy's judgment, with regard to 

 questions of relationship, in this case, as in many others, was a 

 very correct one. 



The genera which he places among the Phytomydae Myodinae 

 are : Dichromya, Palpomya, Hesyquillia, Heramya, Myoris, 

 Oscinis, Blainvillia, Meckelia, Melieria, Myennis, Strauzia, 

 Vidalia, Delphinia, Acidia, Myrmecomya, Polystodes, Sty- 

 lophora, Herina, Myodina, Richardia, Rivellia, Boisduvalia, 

 CUdonia, Setellia, Chlorophora. Concerning these genera and 

 their names, I will offer the following remarks : — . 



The genus Dichromya (the name ought to be improved to 

 Dichromyia) is adopted by Macquart in his Dipteres Exotiques, 

 and placed among his Heteromyzides. The Dichromyia brasil- 

 iensis of Rob. Desvoidy is the same as the Platystoma micro- 

 cera of Macquart's Suites a Buffon, and was described still 

 earlier as Tetanops sanguiniceps by Wiedemann. Not being a 

 Tetanops this species must therefore be considered as the type 

 of the genus Dichromyia. The position among the Ortalidae, 



