Banks, Greene, McAtee, and Shannon — Dist. of Col. Diptera. 181 



Baccha Fabricius. 



B. coGNATA Loew. — Dead Run, Ya., June 22, 1915, in shady woods, 

 Shannon. 



B. CLAVATA Fabricius. — Falls Church, Va., June 16, Banks; District 

 of Columbia, July, 1902. 



B. FASciPENNis Wiedemann. — Falls Church, Va., September 4, 1915, 

 Greene; August 22, Great Falls, Md., July 21, 1916, Banks; Bladens- 

 burg, Md., September 23, 1915, in open woods, Shannon; Plummers Id., 

 Md., June 28, 1905, July 27, 1907, Fisher; Anacostia, D. C.July 26, 



1914, W. D. Appel. 



B. FusciPENNis Say. — Everywhere May 28 to October 11. Most of the 

 Bacchas are found hovering near flowers or near tips of branches, fre- 

 quently of pine trees. Ocyptamus longiventris Loew (Centuria septima, 

 p. 66), described from the District of Columbia is considered a synonym. 



B. LUGENS Loew.— Great Falls, Va., July 17 and 31, Glencarlyn, Va., 

 October 10, Banks; Plummers Id., Md., July 14, 1913, and August 6, 



1915, Maryland near Plummers Id., August 5, 1913, Shannon; Cabin 

 John, Md., July 12, F. Knab. 



B. TARCHETicus Walker. — Odenton, Md., July 18, Banks; Beltsville, 

 Md., July 30 and August 6, 1916, McAtee; Hyattsville, Md., August 4, 

 F. Knab; Plummers Id., Md., July 28, 1907, A. K. Fisher; August 11 

 and 24, 1907, McAtee; August 25, 1907, A. K. Fisher; September 1, 1907, 

 McAtee; Virginia near Plummers Id., Md., June 19, 1909, McAtee; Dixie 

 Landing, Va., August 19, C. H. T. Townsend; Pimmit Run, Va., August 

 1, 1908, F. Knab; Falls Church, Va., July 25, 1913, September 11, 1912, 

 Greene; September 17; Great Falls, Va., July 23 and 31, Banks ; Wash- 

 ington, D. C, July 5, 1909, A. K. Fisher. Bred from Aphid colony, 

 Greene. 



Platychirus St. Fargeau and Serville. 



P. CHAETOPODius Williston.— Rosslyu, Va., August 25, 1912, F. Knab 

 and J. R. Malloch; Chain Bridge, Va., May 28 and September 17, Banks; 

 Maryland near Plummers Id., July 30, 1914, Shannon. The species of 

 this genus occur on flowers sometimes in marshy places. 



P. HYPERBOREUS Staeger. — Almost if not quite as common in its season 

 as P. quadratus, and similar in habits; April 20 to August 6. 



P. QUADRATUS Say. — Common; April 6 to November 5; on many kinds 

 of flowers. 



Melanostoma Schiner. 



M. MELLi>ruM Linnaeus. — About as common as M. obscurum, but the 

 various records are given. Beltsville, Md., June 18, 1916, McAtee; 

 Maryland near Plummers Id., April 23, 1914; May 7, 1913, Shannon; 

 April 23, 30, June 18, 1916, L. O. Jackson; May 10, 1916, McAtee; May 



