The following is a purely provisional grouping of the described North American species of Sapromyza, made up from the descriptions alone. As such, it is offered for publication. The practical use of this kind of work does not need pointing out. It greatly facilitates the identification of species where the descriptions are scattered through various works. In the determination of the single new species described at the end of this paper, it was necessary to consult each description separately. It required but little additional labour to tabulate the leading points in the descriptions, thus relieving later students from the necessity of going through the same laborous process.