NO. 2344. SUPERFAMILY TIPULQIDEA— ALEXANDER AND McATEE. 391 

 RHYPHUS ALTERNATUS Say. 



Common ; dates of collection range from February 28 to July 23 ; 

 has been bred from decayed fungus ; comes to sap. P. I. 



RHYPHUS PUNCTATUS Fabricius. 



Virginia near Plummers Island, September 4, 1903, H. S. Barber; 

 Plummers Island, April 23, 1914, R. C. Shannon; Falls Church, 

 Virginia, July 11, 1912; August 9, 1917, reared from cow dung, 

 C. T. Greene ; June 7, 1914, R. C. Shannon. 



Genus TRICHOCERA Meigen. 



The genus Trichocera at this time presents almost insuperable 

 taxonomic difficulties. The keys and determinations here given must 

 therefore be considered as tentative. The immature stages occur in 

 decaying organic matter. 



KBY TO SPECIES. 



1. Wings more or less distinctly marked with darker 2. 



Wings unmarked, hyaline or subhyaline 3. 



2. Wings with two brown clouds, one near the origin of the sector, the other 



atr-m T. himacula (p. 391). 



Wings with a very faint brown cloud at r-m and less distinct clouds along 

 with branches of Cu T. regelativnis (p. 391). 



3. Mesonotum brownish gray with four brown stripes; wings grayish subhya- 



line T. hiemalis (p. 391). 



Mesonotum clear gray with two stripes indicated only on the anterior por- 

 tion of the sclerite; wings nearly hyaline. (Regional )__T. brumalis Fitch. 



TRICHOCERA BIMACULA Walker. 



The specimens determined as this species were collected at Wash- 

 ington, District of Columbia, November 18, 20, 1913, F. Knab ; No- 

 vember 23, 1906, McAtee; January 5, 1906, Alexander; and at 

 Plummers Island, November 2, 1903, E. A. Schwarz and H. S. Bar- 

 ber; October 27 and December 31, 1906, A. K. Fisher. 



TRICHOCERA HIEMALIS De Geer. 



Washington, District of Columbia, November 4, 1906, F. Knab. 



TRICHOCERA REGELATIONIS Linnaeus. 



Washington, District of Columbia, March 29, 1907, McAtee; Plum- 

 mers Island, February 24, 1903. U. !V ('urrie. 



