66 THOMAS SAY FOUXIJATIOX 



Geirns SARCOPHAGA Meigen. 



The history of the genus is sketched in the Intro- 

 duction, and its principal characters are mentioned 

 there. Being a residual genus of vast extent, its dif- 

 ferential characters for the present purpose are main- 

 ly negative, — the absence of those which mark off the 

 smaller related genera. In the analytical tables which 

 follow, as a safeguard against mistakes by the be- 

 ginner, all the species of the minor genera are in- 

 cluded, except those of the strongly-marked ones 

 Phrissopodia, Wohlfahrtia and Johnsonia. 



Table of Groups. — Males. 



Three distinct postsutural dorsocentrals 



Hind tibia? with villosity (at the minimum 

 there are at least a few erect, slender hairs 

 that are longer than the diameter of the 

 tibia) 



Hypopygium wholly black 



(p. 67) ' Group A. 

 At least its second segment red 

 (p. 74) Group B. 

 Hind tibia? not with erect villosity (at the ut- 

 most with appressed hairs) 

 Hypopygium wholly black 



(p. 94)' Group C. 

 At least its second segment red 

 (p. 113) Group D. 



Four postsutural dol-socentrals, or else the anterior 

 ones of the postsutural series indistinct, hardly 

 differentiated from hairs. 



Hind tibicE with A'illosity (as limited above) 

 Hypopygium wholly black 



(p. 162) * Group E. 

 At least its second segment red 

 (p. 174) Group F. 



