408 NORTH AMERICAN DIPTERA 



29. First vein setose posteriorly between the humeral crossvein and base of 



the wing 30 



First vein bare posteriorly 37 



30. First vein setulose below as well as above 31 



First vein bare below 32 



31. Postsutural acrosticals absent Sarconesia Bigot 



Postsutural acrosticals present Sarconesiopsis Townsend 



32. Face yellow, clothed with yellow hairs 33 



Face black, the hairs black 35 



33. Palpi short and slender Cochliomyia Townsend 



Palpi long, normal 34 



34. Vibrissas situated the length of the second antennal segment above the 



oral margin (13) Hemilucilia Brauer 



Vibrissas almost on a level with the oral margin Chloroprocta Wulp 



35. Aristal rays quite short and appressed; head almost as long as high. 



Boreellus Aldrich & Shannon 

 Aristal rays long, not appressed; head decidedly higher than long 36 



36. Upper lobe of the squamje haired above ^Phormia Desvoidy 



Upper lobe of the squamae haired only on the margin. 



Protocalliphora Hough 



37. Antennae very short, the third segment little longer than the second; 



face receding below, the vibrissae closely approximate. 



Neophyto Townsend 

 Antennge elongate 38 



38. Suprasquamal ridge with erect black hairs 39 



Suprasquamal ridge bare or pubescent 40 



39. Subcostal sclerite setulose Lucilia Desvoidy 



Subcostal sclerite bare Phenicia Desvoidy 



40. Thorax with abundant yellow tomentose hairs among the black hairs 



(14, 23) Pollenia Desvoidy 



Thorax without tomentose hairs 41 



41. Postscutellum strongly developed; propleura bare; prosternum setulose 



laterally; bend of fourth vein broadly rounded (15). 



Mesembrinella Giglio-Tos 

 Postscutellum not developed 42 



42. Three or more sternopleurals 50 



Two sternopleurals 43 



43. Fourth vein ending almost in the tip of the wing 44 



Fourth vein ending well before the tip of the wing 45 



44. Arista long plumose (7, 28) fOposodexia Townsend 



Arista short plumose Opelousia Townsend 



* Protophormia Townsend is separated by the absence of strong acrostical bristles but the 

 character is of not more than specific value in this instance, some specimens possessing 

 distinct acrosticals. 



t Reinhard, 1929, Pr. U. S. N. M.. Ixxvi, Art. 20, p. 6. 



