96 NORTH AMERICAN DIPTERA. 



M U S C I I) J 

 (In the widest sense). 



This very large group, commonly known as the Muscidae 

 sens. lat. has been divided into numerous minor groups, which 

 by many dipterologists have been accredited with family rank. 

 The number and limits of these groups are the subjects of 

 more or less difference of opinion among systematists. The 

 constant tendency, not only in dipterology, but in all ento- 

 mology, is to raise the rank of minor divisions with the in- 

 crease of new forms, and most writers on diptera nowadays 

 give the family termination of idee, to most of the groups 

 of this family or superfamily. This tendency has, however, 

 been carried to an extreme by some recent writers. Whether 

 or not they be considered as families or subfamilies, matters 

 little so long as it is remembered that the distinctive charac- 

 ters have, in general, less morphological significance than 

 among the groups of the Orthorrhapha. 



Brauer divides the group, which he calls Schizophora, after 

 Becher, into the Eumyidse and Schizometopa, which correspond 

 pretty well to the old and well established Calyptratse and 

 Acalyptratae, terms which should not, in my opinion be dis- 

 placed at the option of any systematist who chooses to offer 

 new terms. Nor can I accept the name Schizophora, the well 

 established name of Muscidae, or Muscidea, if one wishes a 

 distinctive ending, is quite as good and more appropriate. 

 That the change of limitations in a higher group gives the 

 changer the right to change the names also, has no more force- 

 ful application here than among the lower groups. No one is 

 sustained in rejecting generic names because he modifies the 

 definition of the genus, as must necessarily be the case with 

 nearly every added new species. 



The following characters will apply to the family or super- 

 family in its entirety : 



