It is unfortunate that Frick (1952), in preparing his generic revision of the Agromyzidae, was unable to examine the types of many species described by Loew, Malloch, Frost, and others. In such circumstances, a few mistakes were bound to be made, and the fact that these are not more plentiful is a tribute both to the quality of the descriptions of the authors concerned, especially Malloch, and to the care with which these descriptions have been analysed. In 1949, being interested in the possibility of using Hendel's (1931) European classification for the North American fauna, I examined 71 of the types in question, and was able without difficulty to reconcile most of them wiih Hendel's generic and subgeneric concepts. Of these types, only 13 are now found to conflict with the assignment proposed for the species by Frick.