Up to the present time the different travellers have found in Madagascar the following Muridae, viz: Mus indicus, rattus and musculus, and the very interesting Hypogeomys antimena. The first three species are probably introduced by vessels, whilst Hypogeomys antimena is peculiar to Madagascar. Last month our Museum received a large collection of Mammals, Birds, a. s. o. gathered in that island by Mr. J. Audebert, in which collection there were three specimens of Mice, which clearly belong to a new species, may to a new genus. For showing the general size and dentition of Mus decumanus, the hind feet are highly enlarged, the ears longer, and the tip for about one sixth the lenght of the tail is ornated with pure white hairs.