In exchanging Coleoptera it is common to find many erroneous determinations of species. While these errors are for the most part individual, several are wide spread and seem to be perpetuated by tradition from the older collectious. The object of this paper principally is to direct attention to a few of the latter.

1. Triplax thoracica Say, and T. flavicollis Lac. These species are often found in colonies feeding together on the same fungus, and have the same appearance. The separation of mature specimens is easy, the under side of thoracica being entirely rufous, while the metathorax and abdomen of flavicollis are black or piceous.