In the P. Z. S. L. of the year 1852, p. 99, we find a description of a new Hyrax from Fernando-Po by Fraser. This new species, Hyrax dorsalis, is rather insufficiently described and the figures (Plate XXXIII) have no value at all. In the following year, 1853, Temminck published his »Esquisses Zoologiques sur la Côte de Guinée” and described a new species of Hyrax, H. sylvestris; was evidently not acquainted with Fraser’s knew Temminck Hyrax, he only Hyrax syriacus, capensis and arboreus. Now I am convinced that Temminck’s species is the same as Fraser’s and although Temminck’s description is very extensive and clear, meanwhile this cannot be said of that of Fraser, the latter having the priority of some months, the species in question ought to be called H. dorsalis. In Temminck’s paper however is a mistake born by the fact that he had not a skull of an adult specimen. So he writes: »le nombre des molaires aux deux mâchoires est de six dans sylvestris; dans arboreus, ainsi que chez les autres espèces, l’etat normal est de sept partout.” I have removed the skull of an adult specimen, one of Temminck’s types, and this skull shows seven molars in each jaw like in fullgrown specimens of the other species, arboreus, syriacus and capensis.