emptdid.t:. 73 



tarsi flattened, etc.; pulvilli |)i-esent, the empodia usuall}- 

 meinbranaceous and linear. Neuration variable ; the discal 

 cell sometimes absent, the third longitudinal vein furcate or 

 simple ; three or four posterior cells present ; anal cell often 

 shorter than the second basal cell, closed before the margin of 

 the wing*; sometimes wholly wanting. 



The family Empidid;^ is a large one, including many genera 

 and species. Most flies belonging here will be at once recog- 

 nized, but there are some, especially those of the subfamily 

 Tachydromina?, which have such })eculiar neuration that they 

 are apt to lead the student astray ; some may even be sought 

 for among the smaller Muscids. The flies are all predaceous, 

 though obtaining part of their food at times from flowers. 

 Many species, especially those of Enqns and Iih.ampho)iiiii(t 

 often fly in swarms, dancing up and down over running brooks, 

 in the shade of trees or about slirubbery. Very rarely do any 

 species reach the length of ten millimeters, and some are not 

 more than three in length. 



The larva? are cylindrical, with small swellings on the under 

 side, from the mesothoracic segments, for locomotion. They 

 are probably carnivorous and live in the earth, under leaves 

 or other decaying vegetable matter. The pupa^ are free, with 

 two porrect points at the anterior end. 



TABLE OF GENERA. '■!--«— 



'^ 1. Anal cell closed in the lionler or narrowly open; ])0(ly without m^vxo- (jikLfi/u^/jU^ , 



Clianaj IllI.AlilMOKPIlIN.E. 



Anal cell closed before the border wlien ])resent. ... 2 



2. Anal cell wanting; when present the front femora shorter or but little 



longer than their coxa^ Tachydkomin.i:. 



Anal cell present; front femora much longer tiian their co.\;«. . o 



* Mythicornpa, a genus of doubtful relationship, has the anal cell open. 

 In Hilarimorpha it is closed in the margin. Both genera also differ from 

 other Empididae in being destitute of uiacrochajtaj. Osten Sackeii and 

 Schiner locate the latter genus among the Leptidiu. If tl:at view is ac- 

 cepted, M iithicinii'iia sliould probably accompany it. 



'.) 



