192 Proceedings of the Biological Society of Washington. 



Facio-orbital row consisting of a bristle or two without hairs 

 above ; vertex but little over one-fourth eye-width ; cheeks 

 about one-fourth eye-length; parafacialia not one-third 

 width of clypeus ; at most a few median macrochaetae dis- 

 tally on hind femora exteriorly .... Parasarcodexia, gen. nov. 



30 — Postsuturals three . 31 



Postsuturals two, with or without two more or less developed 



additional ones in front 33 



31 — Strong median marginals on segment II (the front side of 

 middle femora with a patch of yellow hairs distally in the 



genotype) Sarcotachinella T . 



No median marginals on segment II 32 



32 — Outer verticals developed, strong Bellieria RD. 



Outer verticals not developed ...... Bercaeopsis, gen. nov. 



33 — Parafacialia broader than clypeus; no facio-orbital row to be 



distinguished from the other hairs Wohlfahrliopsis T. 



Parafacialia not as wide as clypeus 34 



34 — Facio-orbital row including several strong bristles below . . 35 



Facio-orbital row consisting only of hairs at the most ... 36 



35 — Vibrissal axis nearly equalling head-height; epistoma well 

 projected beyond vibrissae ; facialia bristled about half- 

 way at most; cheeks over one-half eye-length . Sarcophaga Mg. 

 Vibrissal axis not over three-fourths of head-height; epistoma 

 only slightly projected ; facialia normally bristled well over 

 half-way; cheeks little over two-fifths eye-length .... 



Sarraceniomyia, gen. nov. 



36 — Vertex about two-thirds as wide as eye Bercaea RD. 



Vertex at most but little exceeding one-half eye-width ... 37 



37 — Outer vertical strong Prosthetocirca, gen. nov. 



Outer vertical not developed, vestigial . . Gigantotheca, gen. nov. 



Females. 



Abdomen wholly shining and without pollen Peckia RD. 



Abdomen more or less pollinose 2 



2 — Only one pair of proclinate fronto-orbitals 3 



Two or more pairs of proclinate fronto-orbitals 4 



3 — First hypopygial tergite retractile Sarcophagula Wp. 



First hypopygial tergite modified into a non-retractile perma- 

 nent fifth visible segment of the abdomen Prosthetocirca, gen. nov. 

 4 — No reclinate fronto-orbitals, usually three proclinates . . Agria RD. 

 At least one reclinate fronto-orbital always present, procli- 

 nates two 5 



5 — First vein bristled about half way 6 



First vein bare 12 



6 — Strong, long and erect median marginals on segment II 

 (sides of scutellum with thick patches of hairs on edge be- 

 tween lateral bristles in genotype) Titanogrypa T. 



Median marginals absent, vestigial or weak on segment II . 7 



