In the following lines a very interesting new genus of the group Rhynchophoridae will be established. A single male specimen, from the Upper Mahakam (Borneo), has been found in a small collection of natural history objects, presented to the Leyden Museum in December of last year by Mr. Kampmeinert. The species is dedicated to the donor. The nearest ally of this new genus, for which I propose the name Mahakamia, is Macrocheirus Schönh. The characters by which the two genera are differentiated in the male sex (the female sex of my insect is as yet unknown) are very conspicuous, as will be seen from the following table.