Among a number of species of Erotylidae, sent to me by Mr. Ritsema for determination , there are a great many of the very highest interest. About seventeen are new, including four for which it is necessary to make new genera, while others were up to this time only known by the unique types in the late Mr. Crotch’s or my own collection. I have had unusual facilities for this work, the Cambridge collection, formed by the late Mr. Crotch, being at present in my hand for the purposes of the description of the Erotylidae for the Biologia Centrali-Americana. This collection contains the types from Chevrolat’s, Guérin Méneville’s, E. Sheppard’s, Reiche’s and other collections; my own possesses the West African species from the late Mr. A. Murray’s collection, and I am indebted to Dr. D. Sharp for the opportunity of examining, among other little known species, a type of Tritomidea translucida received from Motschulsky, also Tritomidea rubripes Reitter, Euxestus minor Sharp, Hypodacne punctata Lec. etc. This has been a very great aid to me, for it enables me to say certainly that some species referred by Crotch doubtfully to Tritomidea, and others so referred by myself, have no connection with that genus, and that Tritomidea and some allied genera are at present only doubtfully placed in the Erotylidae, and will form at least a separate sub-family.