The type-specimen (an adult male with skeleton), collected by Beccari on one of the islands of the Arou-Archipelago and described by Peters and Doria in 1875 (Ann. Mus. Civ. Gen. VII) and at the same time the only known individual, has been a puzzle to all students of the Phalanger-group. It therefore is of the highest interest that I found in the Lorentz-collection the three above mentioned specimens, prima facie distinct from all hitherto seen individuals of the orientalis-group, but at the same time exactly agreeing with gymnotis Peters et Doria. During the past summer I could study the type in the Genoa Museum, by the loudness of the Director Marquis G. Doria, so that I am absolutely sure of the identification. It hardly can be supposed that specimens of this species once have been brought over from New-Guinea to the Arou-islands, so that the living of this species both in New-Guinea and on the Arou-islands, is another proof for their land-connection in times past. However, notwithstanding there seems to be no doubt about the original locality — the Arou-islands — it is a very remarkable fact, that nobody since 1875 saw another specimen from the named islands, the more strange as before Beccari our traveller Baron von Rosenberg collected specimens, now in the Leyden Museum, of Phalanger maculatus as well as of Phalanger orientalis on these islands, and Wallace too procured from there specimens, now in the British Museum, belonging to these two species. This may be as it is, it remains however a fact that Peters described the species in such clear terms, that merely lack of material may be an excuse why later authors failed to accept it as a species distinct from Phalanger orientalis. Indeed, extremely striking is the kind of fur and its colour as well as the naked tail, only adorned with a rather small ring of fur round its base; moreover the skull, concave like in orientalis, presents a dentition quite distinct from that of the latter species, especially by the very stout posterior premolar (p4) in the upper- as well as in the lower jaw, placed by far not so correctly in the molar-row as is the case in all other Phalangerspecies.