262 



NORTH amf:ricax diptera 



Abdomen differently colored; posterior femora usually with low ridge 

 on the apical fourth bearing stout, short, spinose setae; head gently 

 convex above from anterior view; abdomen not wholly pale pilose 

 (29, 130) *Hel*iophilus Meigen 



78. Face produced downward, longer than the fi'ont; pale mesonotal 



markings poUinose (120, 129) fSphecomyia Latreille 



Face not conpicuously produced, shorter than the front; if doubtful 

 the pale mesonotal markings are of the ground color 79 



* Shannon, 1926, Proc. U. S. N. M., Ixix, Art. 9, pp. 16, 26 (Xylotoinima, Xylota). 

 t Curi-an, 1932, Amer. Mus. Novit. No. 519, p. 8. 



149 



150 



151 



152 



Syrphidae VIII. — 137, Teuchocnemis lituratus; 138, Pterallastes thoracicus ; 139. Seri- 

 comyia militaris; 140, Mecromacrus cinctus ; 141, Mallota sackeni ; 142, Mecroinacrus cinctus ; 

 143; Eristalis tiansversus; 144, Arctophila flagrans ; 145, Polydontomyia curvipes; 146, Par- 

 helophilus Isetus ; 147, Mallota cimbiciformis ; 148, Polydontomyia, hind leg; 149, Lunoinyia ; 

 150, Asemosyrphus mexicanum ; 151, Lejops stipatus ; 152, Crioprora. 



