20 Everett E. Wehr 



9. Sixth abdominal segment (hypopygium) of male as long as the 

 two preceding ones together, cylindrical ; fifth segment of female 

 one-half as long as preceding Eupeodes 



Sixth segment not peculiar; the fifth segment in the female not 

 over one-half as long as the preceding 10 



10. Small, robust species; abdomen without yellow stripes Paragus 



Large species; abdomen with yellow stripes 11 



11. Front very convex, eyes of male with an area of enlarged facets 

 above (Lasiopthicus, Catabomba) Scaeva 



Front normal, eyes of male not with an area of enlarged facets 

 above Syrphus 



Baccha Fabricius 



KEY TO THE SPECIES 



1. Third joint of the antennae elongate oval, obtusely pointed; face 

 very prominent; abdomen more spatula-like clavata 



Third joint oval, obtusely rounded; face not prominent 2 



2. Wings almost entirely black, a triangular hyaline spot behind 

 the outer end of the third vein, the auxiliary portion more or 

 less subhyaline fuscipennis 



Wings almost entirely hyaline, a quadrangular fuscous area ex- 

 tending across the middle of the wing from the costa to the 

 fifth longitudinal vein lemur 



Baccha clavata (Fabricius). Ent. Syst., iv, 298 (1775); Williston, 

 Trans. Amer. Ent. Soc, xv, 270 (1888). 

 1886. Babista Walker, List., iii, 549 (1849) ; Williston, Synop. N. A. 

 Syrph., 117. 



A s from Lincoln, Lancaster County, in September. 



Baccha fuscipennis Say. Jr. Acad. Nat. Sci. Phil., iii, 100 (1823); 

 Williston, Synop. N. A. Syrph., 119 (1886). 



Four $ $ and three 5 9 taken at Omaha, Douglas County, 

 between August 15 and September 2, 1913 (L. T. Williams). 



126 



