CLASSIFICATION OF THE DIPTERA. 37 



perhaps half-a dozen Indian localities situated in the plains (Puri, 

 Pusa, Purneah, etc.); a comparatively small tract in Travancore, 

 South India (during one visit only) ; several localities in Ceylon ; 

 and perhaps half-a-dozen others in Assam and Burma. These 

 localities do not represent a tenth part of the Indian Empire even 

 allowing a fifty mile radius to each. Realising that the NEMA.- 

 TOCERA themselves only represent a fifth or a sixth part of the 

 whole order of Diptera, the immense possibilities lying before 

 the student will be apparent. 



8. THE CLASSIFICATION OF THE DIPTERA. 



It cannot be said that there is at present any universally 

 accepted classification of the Diptera, although most authors are 

 agreed on Brauer's primary divisions of ORTHORRHAPHA and 

 CYCLORRHAPHA, and the secondary division of the former into 

 NEMA.TOCERA and BRACHYCERA. The lesser subdivisions higher 

 than families, especially amongst the BRACHYCERA, proposed by 

 various authors on different groupings of families, are so numerous 

 that, it would be out of place in the present work to give them in 

 detail, much less to discuss them. 



Williston * gives in full Brauer's, Schiner's, Osten Sacken''s and 

 Coquillett's classifications, in order that the student in his study 

 " may not reach the erroneous conclusion that any system is 

 authoritative." He also gives a classification by a new writer on 

 this subject, Lameere, but this author has been so severely 

 criticised that his views are not included here.t 



The division into ORTHORRHAPHA and CYCLORRHAPHA "may 

 perhaps safely be accepted, since all, or nearly all, are agreed 

 thereon, though by no means agreed as to their rank and limits." 



Osteii Sacken considered that the characters recognised as 

 distinctive of the NEMATOCERA and BRACHYCERA are of more funda- 

 mental importance than those distinguishing the ORTHORRHAPHA 

 and CYCLORRHAPHA, an opinion from which Williston differs, 

 accepting Brauer's primary divisions as the truer biologically. 



By far the most pertinent and concise account of the dis- 

 tinctions between the .NEMATOCERA and BRACHYCERA, and the best 

 and most elaborate synoptical table of families in the latter- 

 division is that in Mr. Verrall's monumental work on " British 

 Flies." t Biological notes of paramount importance are given of 

 each family. 



* " North American Diptera," 3rd edition, p. 52. 



t It seems out of place in the present work to dilate on the classification 

 of this order as proposed by the very earliest writers. The works quoted may 

 be consulted by those readers desiring this information. 



J In vol. v. " STRATIOJIYID.E, etc."; the second of the two volumes at 

 present published. Brauer's descriptions of his suborders and higher groups 

 are translated in Mr. Verrall's first published volume (vol. viii.), and should 

 be studied by those interested in the subject. 



