HELEOMYZID FLIES NORTH OF MEXICO—GILL 603 
ZETTERSTEDT, J. W. 
1838. Insecta Lapponica. Pp. 763-767. 
1846. Diptera Scandinaviae. Vol. 4, p. 1626. 
1847. Diptera Scandinaviae. Vol. 6, pp. 2430-2468, 
U.S. GOVERNMENT PRINTING OFFICE: 1962 
