July, 1893. I 149 



EXPLANATOEY NOTICE OF MY VIEWS ON THE SUB-OEDERS 

 OP DIPTERA. 



BY C. R. OSTEN-SACKEN. 



Through the communications of some of my correspondents since 

 the publication of my paper " On the characters on the three divisions 

 of Diptera, &c." (in the Berl. Ent. Zeitschr., xxxvii, 1892, pp. 417—66), 

 I became aware that some misconceptions prevail in certain quarters 

 about my views on the larger sub-divisions of the Order Diptera, called 

 sub-Orders by Brauer. The fault apparently is on my side, as I have 

 not been explicit enough on pages 426 — 8 (I.e.) of the above quoted 

 paper. On page 423, line 6 from top, instead of "All the other 

 Diptera,^'' I should have put — " Orthorrliapha Brachycera and Cyclorr- 

 hapha Athericera ;" and on page 429, line 18 from bottom, 1 should 

 have added the same five words at the end of the line which begins 

 with the word " foot-note." I beg my readers to make this alteration 

 at once. 



Macquart had two sub-Orders, Nemocera and Brachycera ; Brauer 

 had also two, Orthorrhapha and CyclorrhapJia, but the dividing line 

 between them was at a different place from that of Macquart's. In 

 consequence of the considerations explained at length in my paper, I 

 adopt three sub-Orders, and call them Orthorrhapha Nemocera, Orthorr- 

 hapha Brachycera, and Cyclorrhapha Athericera* (I.e., p. 427, in the 

 middle). In other words, I adopt Brauer's nomenclature, except that 

 his Orthorrhapha Brachycera I consider as a separate sub-Order, while 

 he considered it as a division, which, together with his division 

 Orthorrhapha Nemocera, formed his sub-Order Orthorrhapha. His 

 sub-Order Cyclorrhapha I call Cyclorrhapha Athericera. 



In the same place I said {I.e., p. 426), " Family names in Zoology 

 must consist of one word only ; but there is no inconvenience in using 

 compound names for larger divisions. They are not exactly names but 

 designations, they must have something of the descriptive character 

 in them, &c." 



The three names of the sub-Orders which I adopt have the ad- 

 vantage of being descriptive of a character taken from their 

 metamorphoses on one side, and of another character taken from the 

 imago and its principal organ of orientation (the antennae) on the 

 other. The names Orthorrhapha and Cyclorrhapha were very happily 

 chosen by Brauer to characterize the metamorphoses of each of the 

 groups, and should therefore be preserved. The names Nemocera and 



* Derived from the Greek ailur, arista, awn, and kexai, horn. 



