TAXONOMY OF MUSCOIDEAN FLIES — TOWNSEND 45 



It is also believed that the five families into which the Muscoidea 

 are divided will ultimately be found to closely correspond in value 

 with the families now recognized in the other divisions of the 

 Cyclorrhapha. • 



Professor *]. H. Comstock published a very able paper in the 

 Wilder Quarter Century Book, setting forth certain suggestions as 

 to taxonomic work. The idea is there elaborated that, in order to 

 determine the proper taxonom.ic system for a given group of insects, 

 the forms should be arranged independently on each one of their 

 many characters in turn, and the final mean between all these sepa- 

 rate arrangements should then be determined. This mean 'would 

 indicate the correct taxonomic system. It is understood, of course, 

 that the varying values of the various characters should be taken 

 into consideration in such a procedure. It has been the aim to pre- 

 sent a systematic arrangement in this paper to agree quite closely 

 with the results that might be obtained from such a final average 

 between characters in this-superfamily. 



In the following synoptic treatment of taxonomic categories a plan 

 is followed which has been devised and perfected by Dr. A. D. Hop- 

 kins, to whom thanks are due for an exposition of it. This synoptic 

 plan possesses decided advantages over any scheme of the kind yet 

 devised, and is really a perfected system on the lines of that used by 

 Brauer and von Bergenstamm, and some other European system- 

 atists. The present synopses are carried down to families only, and 

 do not exhibit the plan in detail. It will be a labor of years to per- 

 fect the arrangement of the forty or more subfamilies, the numerous 

 tribes, the two or three hundred American typic genera and five 

 hundred or more additional atypic genera in this superfamily, to say 

 nothing of the multitude of typic and atypic species. The synoptic 

 plan referred to is carried out in detail by employing the following 

 system of characters in turn : I, II, III, etc. ; A, B, C, etc. ; ai, a2, a3, 

 etc. ; bi, b2, b$, etc. : ci, C2, C3, etc. 



Order DIPTERA 



Lunula absent Suborder Orthorrhapha 



Lunula present Suborder Cyclorrhapha 



Suborder CYCLORRHAPHA 



Ptilinal suture absent Series Aschiza 



Ptilinal suture present Series Schizophora 



Series SCHIZOPHORA 



Head closely united to thorax or folding- back into dorsal groove on same. 



Section Pupipara 

 Head separated from thorax by a free neck Section Myodaria 



