DIPTERA OF MINNESOTA. 93 



the most common flies found on windows should not be drawn from 

 the name." House flies, various Anthomyiids, Sarcophagids, and 

 members of various other famiHes, are commonly seen on windows, 

 many of them, to the uninitiated, looking as though they belonged 

 to the same species, although they may be representatives of different 

 families. We only have about ten Scenopinid species in North 

 America. 



The adult flies of this family are black ; the long, slender larvae are 

 found in decaying fungi and in wood. They are supposed to be carni- 

 vorous. 



Scenopinns fenestralis, Linn., is found in Minnesota. 



EMPIDAE or EMPIDIDAE, 



Dance-Plies. 



This is a large family, Aldrich giving 432 species as occurring 

 in North America alone, and about 200 species are known in Great 

 Britain. They are medium sized flies of dull colors, brown, gray or 

 black. The legs are long, sometimes hairy, and most of the species 

 have a pointed beak. They are predaceous, preying upon smaller 

 flies and other insects, the female being particularly savage, and using 

 her rostrum, or beak, for piercing and sucking her victims. They are 

 also found on flowers. 



In one genus, Hemerodromia, the femurs of the front legs have 

 spines against which the fore tibise close. This contrivance evidently 

 serves the purpose of a trap. The flies of this family are well referred 

 to as "Dance Flies," since some species perform quite extensive aerial 

 gymnastics, and are often seen in this act near shrubbery or over 

 brooks. Jn these dances some are said to carry silken veils or nets. 

 These webs or nets may assist in capturing other insects, and may also 

 be of use in courtships. 



The following clipping from the Elgin (Minn.) Monitor probably 

 refers to flies of this family. 



A SINGULAR PHENOMENON. 



A singular phenomenon was witnessed about town Tuesday afternoon 

 when Frank Adams, who was sitting in his wheel chair on the lawn at his home, 

 discovered that the air was literally full of delicate white silvery webs. He 

 failed the attention of a number of our citizens to it, who witnessed the same 



