RHOPALOMERIM. 281 



Sapromyzidse. I know nothing of their habits, whether 

 in the adult or immature stages, though I suspect that 

 they are denizens of wet or damp places. The known 

 species are confined to Central and South America. 



The group is evidently sharply divided into two minor 

 groups, by the presence or absence of the auxiliary vein 

 and the length of the first longitudinal vein. 



TABLE OF GENERA, 

 i. Auxiliary vein wanting, the first longitudinal vein short; first pos- 

 terior cell of the wings not narrowed; palpi slender [Rhinoto- 



rincc) Rhinotora. 



Auxiliary vein well-developed, the first longitudinal vein longer; 

 first posterior cell much narrowed in the margin; palpi dilated 

 ( Rhopalomerince) ......... 2 



2. Scutellum oval; arista plumose. ...... 3 



Scutellum pyramidal, directed obliquely upward; arista plumose or 



bare (3, 7, p. 34) Rhopalomera. 



3. Front with bristles; face carinate; hind tibiae dilated and with tuber- 



cles (1) Willistoniella, Mik. 



Front without bristles; face tuberculate; hind tibiae slender (South 

 America) . ... Apophorhynchus Williston. 



