In 1941 and 1942 I studied the rather extensive collection of Erotylidae in the Rijksmuseum van Natuurlijke Historie, the results of this study are given in the following pages. The collection is chiefly composed of material which during a long series of years gradually was acquired by the Museum, though a great deal formerly was a part of private collections which later as a whole became the property of the Museum and then the specimens were incorporated into the general collection. The most important of these private collections is that of Dr. H. J. Veth, other important collections are those of Dr. D. MacGillavry, and of Mr. J. J. de Vos tot Nederveen Cappel, the latter collection recently presented to the Museum. Moreover the Museum possesses certain collections which have to remain as separate units besides the general collections. Erotylidae are contained in some of these, viz., that of Jhr. Dr. E. J. G. Everts (the standard collection of Netherlands Coleoptera), that of Mr. A. E. Kerkhoven, and that of Mr. A. J. F. Fokker van Crayesteyn van Rengerskerke. Under each species the material of these collections is mentioned after that of the general collection of the museum. Several specimens proved to be representatives of new species or new varieties, these are described in the following pages. Among these there are a number which were labelled by P. Kuhnt with a new name, which apparently never was published. I have named these species with the museum names already given to them by Kuhnt, as also in other collections these names may be already present. Behind the name of each species the measurements are given in mm, these measurements (length, and in several cases also the maximum