This paper is a continuation of Büttikofer’s papers on the zoological researches in Liberia in the Notes from the Leyden Museum, 1885, Vol. VII, p. 129 and 1886, Vol. VIII, p. 243. As well as Büttikofer’s list of the birds gives a good impression of the richness of the Avifauna in that part of Africa, so my paper will give an idea of the luxuriousness of the Mammalian forms in that country. Our travellers have been happy enough to procure several new species besides specimens of species hitherto only known by mutilated skins or by a single skull, by a single specimen or of which the locality was unknown or uncertain. The collections are the results of four voyages, made by Büttikofer and Sala (January 1880—April 1882), by Stampfli (July 1884—April 1886), by Büttikofer and Stampfli (November 1886—May 1887) and the continuation of the latter by Mr. Stampfli who is still hunting in Eastern Liberia, but intends to return within a few months. In the above mentioned paper (1885) on the birds of Liberia, Büttikofer has giveu a very clear and interesting introduction treating on the physical condition of Western Liberia. In an expected paper Büttikofer intends to enter in some details on the Eastern parts of that country, the field of bis later investigations; be will adjoin a sketch of the latter part of Liberia embracing the Junk-, Du Queah- and Farmington Rivers. Nearly every species he procured has given opportunity to Büttikofer to make biological observations, which he always very eagerly collected and which I add hereafter in the German language. If we peruse the following pages and Buttikofer’s papers on the Liberian birds and we consider that Reptiles and Fishes, Mollusks and Insects have been collected by our travellers on the same large scale and in the same exhausting manner, then we must wonder that Büttikofer has found time for such extensive observations concerning Botany, Ethnology, Anthropology , Geography, Meteorology and Philology as he made and which he partly published in a Dutch journal (Tijdschrift van het Nederlandsch Aardrijkskundig Genootschap, 1883, Bijblad n° 12). I think that no traveller before Büttikofer, under such bad conditions and in such a murderous climate has gathered such an enormous mass of donnés in every branch of science and that in the short time of a few months.