94 DIPTERA OF MINNESOTA. 



phenomenon. The tops of buildings and trees were literally covered, and 

 fleecy white masses were seen floating in the air, hundreds of feet above the 

 highest trees. 



By constant observation, Frank discovered that the air was infested by 

 myriads of little flies, but with bodies much smaller than the bee, and of an ex- 

 quisite pure downy white, and that these little insects were spinning millions of 

 delicate silvery white webs, not only enveloping the earth, but filling the air as 

 far as eye could reach with a silvery sheen. Frank captured a number ot the 

 flies, but could find no one who could tell him anything about them. It is not 

 infrequent to find the plants, trees and shrubbery, of a morning, covered with 

 tiny spiders' webs, but to see the myriads of little flies spreading their delicate 

 laces over the surface of the earth, is at least an interesting experience. 



The maggots are found in decaying vegetable matter, though it 

 is possible they feed upon other animal matter found there. 



We have found the following species in Minnesota, which list, 

 however, probably only represents a fraction of what occurs here : 

 Hyhos, sp. ; Rhamphomyia, sp. ; Hilara, sp. ; Rhamphomyia luteiventris, 

 Loew. ; R. dcbilis, Loew. ; R. irregularis, Loew. ; R. priapulus, Loew. ; 

 R. pulla, Loew. ; R. limhata, Loew. ; Hilara macroptera, Loew. ; 

 Syneches thoracicus, Say ; S. pusilhis, Loew ; Euhyhns, sp. ; Syndyas 

 polita, Loew.; Empis nuda, Loew.; E. otiosa, Coq. ; Platypalpus crassi- 

 fenioris, Fitch ; Platypalpus, sp. ; Hemcrodromia empiformis, Say ; 

 H. ro gat oris, Coq. 



DOLICHOPODIDAE, 



The Long-legged Flies. 



Another large family, 380 North American species being listed by 

 Aldrich. Great Britain claims over 200 species. Referring to the 

 above scientific name, Comstock fittingly remarks : "It must be remem- 

 bered, however, that these flies are long-legged only in comparison 

 with the allied families, and not in comparison with crane flies and 

 midges. They are rather delicate, slender insects, for the most part, 

 with metallic coloring, golden or green, and the males of some of the 

 genera characterized by the expansion of the feet, or antennae or other 

 organs, which are probably to be regarded as ornaments used in 

 courtship." 



Aldrich, in speaking of this family, and referring to the great 

 variety and complexity of the sexual adornments of the males, says 



