In two bottles with Reptiles and Fishes from the island of Riouw (lying south of Malacca) sent over by Mr. A. H. G. Blokzeyl, formerly Resident of the Riouw Archipelago, and kindly presented by him to the Leyden Museum, were also a few Arthropods. Of these, eleven species belong to the Coleoptera, and as there is, as far as I know, nothing known of the Coleopterous fauna of this group of islands, I thought it not without interest to give a list of these species, all belonging to the families Scarabaeidae (4 spec.) and Cerambycidae (7 spec.).