24 PROC. ENT. SOC. WASH., VOL. 22, NO. 2, FEB., 1920 



L. sicula McAtee. Great Falls, Va., June 29, 1915, August 

 17, 1916, August 28, 1917, C. T. Greene; June 12, July 21, Banks; 

 Scott's Run, Va., July 25, 1915, McAtee; Langley, Va., July 16, 

 1911, W. D. Appel; Dead Run, Va., June 9, 19, July 25, 1915, 

 R. C. Shannon; Falls Church, Va., July 3, 1916, J. N. Knull; 

 July 20, 25; Glencarlyn, Va., July 13, Banks; Plummers Island, 

 Md., June 18, 1914, R. C. Shannon; June 30 (in copula), July 

 14, 21, 1907, A. K. Fisher; Lakeland to Riverdale, Md., July 14, 

 1916, McAtee. 



L. canis var. canis Williston. Great Falls, Va., June 29, 

 Banks; Plummers Island, Md., June 4, 1916, H. L,. Viereck; 

 Virginia near Plummers Id., Md., June 7, 1908, McAtee; Dead 

 Run, Va., June 28, Banks; July 18, 1916, R. C. Shannon; Chain 

 Bridge, Va., May 28, Banks; Glencarlyn to mouth of Four Mile 

 Run, Va., June 11, 1916, McAtee; Falls Church, Va., July 3, 



1916, J. N. Knull. 



L. winnemana McAtee. Plummers Island, Md., June 27, 

 1915, R. C. Shannon; July 11, 1909, Scott's Run, Va., August 12, 



1917, McAtee; Dead Run, Va., July 11, 1915, July 18, 1916, 

 July 28, 1915, R. C. Shannon; Great Falls, Va., June 28, 1917, 

 C. T. Greene; Maryland near Plummers Id., June 30, 1914, R. 

 C. Shannon. 



L. saffrana Fabricius. St. Elmo, Va., F. C. Pratt. Although 

 Fairfax, Va., is rather out of the District of Columbia fauna, it 

 is worth mentioning that a specimen of this large and handsome 

 species of decidedly southern range has been taken there. 



Dasyllis Loew. 

 Key to the Species. 

 A. Mystax chiefly black. 



B. Tufts of hair in front of halteres and wings black; hair on anterior 



two pairs of legs and thorax pale greenish yellow affinis. 



BB. Tufts of hair in front of halteres and wings yellow; hair on legs 



chiefly black; on thorax bright yellow thoracia. 



AA. Mystax chiefly yellow. 



C. Tufts of hair in front of wings chiefly yellow; lateral margin of first 



abdominal segment separated from that of second by a deep in- 

 cision; large species 28-35 mm. long, including wings grossa. 



CC. Tufts of hair in front of wings chiefly black; first abdominal segment 

 not so separated ; smaller species. 



D. Scutellum yellow-haired; abdomen wholly black flavicollis. 



DD. Scutellum black-haired. 



E. No yellow hair on abdomen virginica. 



EE. Yellow hair on abdomen. 



F. Segments 1-3 of abdomen with somewhat diamond-shaped 

 black, central areas, bordered by broad patches of 

 yellow hair chant plaini. 



