398 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.58. 



NEPHROTOMA XANTHOSTIGMA Loew. 



Great Falls, Virginia, August 15, 1915, McAtee; Falls Church, 

 Virginia, May 25, Glencarlyn, Virginia, June 20, Banks; June 8, 

 1918, McAtee; Hyattsville, Maryland, August 14, 1912, F. Knab; 

 Eastern Branch near Benning, District of Columbia, August 29, 

 1915; Odenton, Maryland, July 29, 1917, McAtee. 



Genus TIPULA Linnaeus. 



KEY TO SPECIES. 1 



1. Wings with a distinct pubescence in the apical cells 2. 



Wings entirely glabrous 4. 



2. Coloration bright shiny yellow, reddish and black ; vertex shiny, with 



a black spot along the inner margin of each eye and a linear dark brown 

 median area ; thorax yellow with three shiny reddish stripes, the median 

 one narrowly divided; male antennae very sliort, not attaining the wing 

 l>ase; pubescence of the wings confined to cell Ra. (Subgenus Odontoiijmla 



Alexander) T. (O.) unifasciata {]). 403). 



Coloration dull brown and yellow ; vertex opaque without black marks ; 

 praescutum dull, dark colored with paler stripes ; male antennae elongate, 

 reaching about to the base of the abdomen ; pubescence of the wings more 

 extensive, including cells Ra to il/2. (Subgenus Cinctotipula Alexander 3. 



3. Antennal flngellum bicolorous; abdomen without distinct crossbands 



T. (C) uniinaculata (p. 403). 

 Antennal flagelluni unicolorous; abdomen with the posterior half of each 

 segment brown, tlie basal half more yellowish, producing a banded appear- 

 ance T. (C.) olgonquin (p. 403). 



4. Coloration as in the genus Nephrotoma, sliiny, contrasting yellows and 



blacks 5. 



Coloration dull brown, gray, yellow, or blackish, not at all shiny 6. 



5. Head orange yellow, the occiput with a grayish black spot; praescutum 



orange yellow with three dull gray-black stripes; posterior half of the 

 postnotum and the apical half of the first abdominal segment light 



gray T. collaris (p. 404). 



Head orange yellow, with a large brownish orange spot on each side of the 

 vertex touching the inner margin of the eye ; praescutum shiny, light 

 honey yellow, with three shiny jet-black or reddish-black stripes; pos- 

 terior margin of the postnotum and the apical half of the first abdominal 

 segment not gra.v. (Regional) T. nnhilis (Loew). 



6. ^\■ings striped or streaked longitudinally with brown or reddish brown, this 



including the costal region and along Cu; cell M usually hyaline or nearly 

 so; male hypopygium with the sclerites of the ninth segment fused into 



a continuous ring (tricolor group) 7. 



Wings not srriped or streaked as above, the costal margin darkened in 

 some cases, but if so with no brown scams on the other veins 13. 



7. Wings with cell Ra hyaline or nearly so, at least on its apical half, thus 



being continuous or nearly so with the area in cell M 8. 



Wings with cell Rt infuscated, concolorous with cells Rs and J/i IL 



8. Large species, wing of the male over 20 mm. ; base of cell R^ darkened 9. 



Smaller species, wing of the male under 18 mm. ; cell R^ hyaline 10. 



'No especial effort has been made in this paper to separate the females of this difficult 

 and complex genus. 



