While arranging the flies of this family contained in the Garry de N. Hough collection of the University of Chicago, together with my own material, a number of notes have been made, which are here given. This family, like a number of other dipterous groups, needs monographic study owing to the confused and scattered descriptions of most of the forms. Of recent years the number of genera has been multiplied, although the authors have neglected to sift out the older species belonging to these new groups. Accordingly, the older genera, like Sargus for example, contain species of several of the modern subdivisions.