372 C. R. Osten Sachen: 



The Position of the Jr^laiypezidae and Pipunculidne I leave 

 entircly in abeyance. According to the recent arrangenients (Becher, 

 1. c), they are placed with Phora and the Siirphidae among the 

 Cy clor rhu plia Achiza, and form with Phora a separate group, Hy- 

 pocera, Here again, as in the case of Phora, I place a certain 

 reliance on the observed motions of the flies. An agreenient in pe- 

 culiar motions, must, it seems to me, correspond to some deep-seatcd 

 agreenient in the Organization. Seh in er (Fauna I, p. 239) and quite 

 independently of him, W. A. Snow (Kans, Univ. Quarterly 1S94, 

 p. 147) describe a manner of flying of Platypezae similar to tliat 

 which I have described above, as observed by me in Phora, Phyphiis, 

 Hyhos, bnt never in a cyclorrliaphe Dipteren, 



There still exists an obscure borderland between the Ortho- 

 rrhapha and Cyclorrhapha which, I snppose cannut be unravcllcd 

 without resorting to anatomy. 



The three Superfamilies Tromöptera, Mydaidae and Energö- 

 poda must, according to my proposition, be added after the Ere- 

 ■mochaeta in the concise tabular arrangement which I published in 

 the Ent. M. Mag. 1893, p. 150. The last Subordcr in that table, 

 the Cyclorrhapha Atheiicera, is now under the care of MM. Th. 

 Becker and E. Girschner, who may succecd in introducing a 

 satisfactory distribution, based upon the new characters which they 

 have recently discovered. 



The tabular arrangement of 1893 would then appcar as follows: 



Suborder I: Orthorrhapha Nemocera. 



Superfaniily : Nemocera vera. 



„ Nemocera anomala. 



Subordcr II: Orthorrhapha Brachycera. 

 Supcrfamily : Er e m o c h a e t a. 

 „ Tromöptera. 



„ My daidae. 



„ Energöpoda. 



Suborder III: Cyclorrhapha Athericcra. 



Tho scqucnce of the four Superfamilies of the Orthorrhapha 

 Brachycera in this arrangement seems to me a matter of little mo- 

 ment. The Eremochaeta contain the greatest numbcr of still sur- 

 viving ancestral forms and may therefore represent an anterior, more 

 ancient zoological horizon, involving covert aftinities to more than 

 one of the othcr Superfamilies of the same Suborder. 



It is a matter of course, although too often forgottcn, that, in 



