ORTALID^ — INTRODUCTION. 



21 



In the Dipteres Exotiques, after the families I have enume- 

 rated the Helomyzidx and Geomyzidse follow, and after them 

 the 



Heteromyzida. 

 Heteromyza, 

 Actora, 

 ! Dicbromyia, 

 Ccelopa. 



In examining the systematic distribution, introduced by Mac- 

 quart in the Suites & Bvffon, we soon find that as early as that 

 work, he had, if not a definite knowledge, at least a correct in- 

 stinct of the true characters of the Ortalidse, less correct, how- 

 ever, than Rob. Desvoidy, who wrote before him. 



Those genera which, in that work, he united in the family 

 Ortalidx really belong to it, with the exception of Rhopalomera 

 and, very probably, of Cleitamia; the latter genus seems to be 

 hardly distinct from Henicoptera, which belongs to the Try- 

 petidae. 



A double error seems to be contained in the separation of the 

 genera Tetanops, Pyrgota, Otites, and Dorycera from the Orta- 

 lidx and their combination with Orygma, Trigonometopus, 

 Eurina, Psilomyia, and Platycephala into one family, the Psi- 



