SrAT(mYZID^.. 129 



Antliomyidw, but the characters above given will in most 

 cases render the differentiation a matter of little difficulty. 

 Still, it is evident that the two families run closely together, 

 and the student will sometimes be in doubt. The family as 

 here accepted is that of Becker, who has recently given an 

 exhaustive study to the European forms. He has established 

 a considerable number of new genera, many of which will un- 

 doubtedly be found to occur in North America. For that 

 reason, I have thought it best to give a translation of his 

 tables of the genera, with but slight modifications or abbrevia- 

 tions. 



The genera so far recognized in North America are Scato- 

 phaga, Hydro in i/za, Norellia, Cordyhira and Cleigastra in 

 their wider sense. FuceUla, Becker refers to the Anthomyidse. 

 The species of Scatopliaga are for the most part yellowish 

 brown in color, the males often with wooly hair. The flies 

 are frequently found about excrement, but they also feed upon 

 other insects, which they capture. Species of Cordyhira and 

 Cleigastra are mostly slender and cylindrical, and of mod- 

 erately large size. They are usually found in meadows or 

 other moist places. The larvae are cylindrical, thin-skinned, 

 the mouth hooklets short and thick, the anterior stigmata 

 large, projecting, reniform in shape, the posterior stigmata 

 situated on rounded eminences. The larvae of NorplUa spini- 

 mana have been found in the stems of B/umex ; those of 

 Cordylura convallarioi in the stems of ConvallfTia ; those of 

 species of Cleigastra in stems of Rnmex, from swine-dung 

 and from the larvae of Noctim ; those of Hydromyza from 

 Nu'phar. 



TABLE OF GENE 1? A. 



1. Protlioracic and stigmatic bristles wanting ; a sternoploural bristle pres- 

 ent, sometimes wanting. 'J'liorax with five dorsocentral bristles, or 

 if fewer, the palpi broad. Scutellum with at least four bristles. 

 Wings usually long. ......... 2 



