116 THE CANADIAN ENTOMOLOGIST 



Scutellum rounded, convex Neogaurax, n. gen. 



22. More than two bristles present on posterior part of 



notapleura • 23 



US Only two bristles on posterior part of notapleura 24 



23. Generally four notapleural bristles present; mesonotum with a 



row of bristles on or near to posterior margin; scutellum with 

 about eight marginal bristles; proboscis not 



elongated Eugaurax Malloch. 



Notapleural bristles very numerous, the whole mesonotum 

 thickly setulose; scutellum subtriangular, disc thickly setu- 

 lose, apical bristles approximated; proboscis elongated and 

 geniculated Chactochlorops, n. gen. 



24. Outer cross-vein absent DicrcBus Loew. 



Outer cross-vein present . , 25 



25. Proboscis elongated and geniculated, mouth margin slightly 



produced and with a«hair-like bristle at vibrissal 



angle Madiza Fallen. 



Proboscis fleshy, very slightly or not at all elongated, vibrissal 

 hair absent 26 



26. Mesonotum with three distinct longitudinal 



sulci Tricomba Liog . 



Mesonotum not sulcate . Botanobia Liog . 



From an examination of the material contained in several 

 collections, and the descriptions by many previous authors, I find 

 that in many cases species are placed in wrong genera, and purpose 

 at some future time publishing notes in addition to those presented 

 herewith as a guide to those who may have occasion to identify 

 specimens belonging to this family. 



Notes and Descriptions: 



Neodiplotoxa, n. gen. 



This genus I have erected for the reception of Diplotoxa nigri- 

 cans Loew. Owing to the fact that this species has the hind 

 femur very much thickened, and the hind tibia bent, it is impos- 

 sible to locate it except in Meromyza by the use of the older keys to 

 the genera. It differs, however, very considerably from Meromyza 

 in the structure of the antenna. 



Type: Diplotoxa nigricans Loew. 



