408 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. o8. 



Genus GERANOMYIA Haliday. 



KEY TO SPECIES. 



1. Wings heavilj' spotted with dark brown; tips of tlie tibiae blaclv 



a. rv.sirata (p. 40S). 

 Wings unmarked or witli only pale indistinct seams along the cord 2. 



2. Sc .short, ending opposite or just beyond the origin of Rs; crossveins and 



deflections of veins faintly seamed with darker, (Regional.) 



O. diversa Osteu Sacken. 



Sc long, ending at about midlength of Rs; wings unmarked except for the 



stigma spot 3. 



3. Body coloration yellow ; wings with the stigma pale ; legs dull yellow, the 



femora not darkened at their tips G. distincta (p. 408). 



Body coloration yellowish brown, darkest on the scutal lobes and the 

 postnotuni ; wings with the stigma oval, dark brown, well defined ; legs 

 brownish yellow, the femora brown at the tips G. canadensis (p. 408). 



The adult flies of this genus feed on various flowers, especially the 

 Compositae and Umbelliferae. The immature stages were until 

 very recently quite unknov/n. In 1918 Mr. J. R. Malloch found the 

 larvae and pupae at Urbana, Illinois. The larvae are acquatic with 

 habits very similar to Dicranomyia si?nulans, living in silt-covered 

 tubes on the exposed faces of rocks over which a thin sheet of water 

 pours continuously. 



GERANOMYIA CANADENSIS Westwood. 



Plate 23, fig. 2. 



Common; dates of collection range from May 2 to October 26; 

 found upon flowers of Asfer, Solidago, Verhesina alternifolia and 

 Eupatorium ageratoides. P. I. 



GERANOMYIA DISTINCTA Doane. 



Beltsville, Maryland, June 20, 1910, June 23, 1918, McAfee. 



GERANOMYIA ROSTRATA Say. 



Frequent; season May 1 to October 7, known to visit flowers of 

 Verhesina and EupatoHwm. P. I. 



Genus DISCOBOLA Osten Sacken. 



The immature stages of members of this genus live beneath the 

 bark of trees, especially of conifers. 



DISCOBOLA ARGUS Say. 



Dead Eun, Virginia, May 23, 1915, R. C. Shannon ; Virginia near 

 Plummers Island, October 28, 1905, H. S. Barber; Rosslyn, Virginia, 

 October 6, 1912, F. Knab; Plummers Island, July 21, 1912, McAfee; 

 Washington, District of Columbia, August 28, Nathan Banks. 



