This treatise on Fur-bearing Animals of North America, prepared by Dr. Elliott Coues, is published as a specimen fasciculus of a systematic History of North American Mammals, upon which the author has been long engaged. It is believed that the Monograph satisfactorily reflects the present state of our knowledge of these animals, and forms a desirable contribution to the literature of the general subject. The Muselidae, like most other families of North American mammals, have not been systematically revised for many years, during which much new material, hitherto unused, has become available for the purposes of science.