343 



This species is undoubtedly the commonest of the genus. It was 

 originally described from Illinois and Wisconsin, and has since been 

 recorded from Montana, southern California, Colorado, New Jersey, 

 and "the Atlantic States". It occurs commonly on tree-trunks in June, 

 July, and August throughout Illinois. 



Townsend has described the puparium and pupa, and given a brief 

 account of the habits of the species*. 



Xylomyia parens Williston 



Subnla parens Williston, Can. Ent., Vol. 17, 1885, p. 122. 



Described from Washington State and not subsequently recorded. 



Xylomyia Americana Wiedemann 



Xylophagus americanus Wiedemann, Dipt. Exot., Vol. 1, p. 51. (1821) 



This species was originally described from "North America." It 

 has since been recorded from Mexico, Illinois, and Pennsylvania. I 

 have before me an example from Urbana, 111., taken June 17, 1916; 

 on a window, and one bearing the label N. 111., which, I am informed, 

 stands for Algonquin or vicinity. 



Xylomyia aterrima Johnson 



Xylomyia aterrima Johnson, Ent. News, Vol. 14, 1903, p. 24. 



This species was originally described from examples from north- 

 ern Illinois and Fredonia, N. H. 



It is unrepresented in our Laboratory collection. 



Xylomyia rallidifemur n. sp. 



Male. — Head brownish black; 2 spots above bases of antennae and 

 the face whitish pilose; antennae blackish brown, reddish on inner 

 side of basal half ; proboscis and palpi yellow- Thorax reddish brown, 

 blackened behind humeri, above-bases of wings, in front of scutellum, 

 on a vertical area on anterior half of mesopleura and sternopleura, on 

 the greater portion of the hypopleura, and at the center of postnotum ; 

 yellow marks cover the whole of humeri, both sides of the transverse 

 suture narrowly, all of the pleurae except the black portions, and the 

 center of scutellum. Abdomen reddish, the dorsum more or less in- 

 fuscated. Legs pale yellow, hind pair more reddish yellow ; anterior 



*Ent. News, Vol. 4, 1893, p. 163. 



