Last year we received trom S. C. I. W. van Musschenbroek, Ex-Resident of Menado, a large collection of Mammalia and Birds; and among them the following species of the genus Mus of Celebes. Four species are new to science and another species is new to the Celebian Fauna. It should here be observed, that the different authors, describing new species of Mice, have not paid attention enough to the nature of the fur which is nevertheless of special importance. For instance, Mus speciosus and Mus argenteus, both described and figured by Temminck, Fauna japonica, 1843, p. p. 51 and 52, tab. 15, may be very easily confounded. Reading the descriptions one would think them to be the same species, the only difference being the longer tail of Mus argenteus. But in studying the types found in the Leyden Museum, it is evident that Temminck has omitted to remark that the fur of Mus argenteus consists of woolly hair only, that of Mus speciosus on the other hand of hair which is woolly and spinous. In fact, in the latter species the woolly hairs of the upper and lower parts of the body are mixed with numerous flexible spines: on the back they are slate-coloured near the base, rusty towards the tip, on the belly they are entirely white; the woolly hairs being here slate-coloured near the base and for the rest of a pure white.