190 Proceedings of the Biological Society of Washington. 



all-important to know what species belong together. When 

 these groups are properly segregated, the species can be studied 

 to advantage. The elucidation of the genera carries with it a 

 knowledge of both sexes of the component species, which is the 

 necessary antecedent to the male genitalic separation of the 

 forms. In the light of such study it is found that the complex 

 has lodged many forms which can not be admitted to the tribe 

 Sarcophagini. 



Genera of Sarcophagini. 

 Males. 



Abdomen absolutely devoid of pollinose covering, polished 



and shining Peckia RD. 



Abdomen always with more or less pollinose covering, not 



wholly shining 2 



2 — One pair of proclinate fronto-orbitals 3 



No proclinate fronto-orbitals 4 



3 — Parafacialia with at most a single row of fine hairs . Sarcophagula Wp . 

 Parafacialia with two or more irregular rows of fine hairs . . 



Sarothromyia BB . 



4 — All tibiae long-villous 5 



None of tibiae long-villous 6 



At least the hind tibiae long-villous, either thickly or thinly, 



but the front ones not 25 



5 — First vein bare Paraphrissopoda T. 



First vein bristled about half way . . . . Tulaeopoda, gen. nov. 



6 — First vein bristled about half way 7 



First vein bare 12 



7 — Frontals not divergent, stopping practically at base of antennae 8 



Frontals diverging at least one bristle below base of antennae 10 



8 — No median marginal macrochaetae on segment III 



Andinoravinia, gen. nov. 



Median marginals present on segment III 9 



9 — Parafacialia as broad as clypeus Argoravinia, gen. nov. 



Parafacialia not as broad as clypeus . . . Chaetoravinia, gen. nov. 

 10 — Strong, long, erect median marginals on segment II ( patch of 

 thickly-placed hairs on edge of scutellum on each side in 



genotype) Titanogrypa T. 



No median marginals on segment II 11 



11 — Outer vertical developed Sarcodexiopsis, gen. nov. 



Outer vertical not sufficiently developed to contrast with 



occipito-orbital fringe Helicobia Coq. 



12 — Frontals stopping practically at base of antennae, not diver- 

 gent except as they follow frontalia 13 



Frontals diverging at least one bristle below base of antennae 17 



