THIS is a companion volume to the “Distribution of Bird-Life in Colombia,” forming vol. 36,1917, of the Bulletin of the American Museum. It differs from many other valuable ornithological books in the fact that at least one-third of it is most interesting reading, and not for specialists in ornithology alone. The introductory chapters, after giving a review of the history of Ecuadorean ornithology, and describing the work done in Ecuador by the American Museum's expeditions, partially under the leadership of the author himself, describes clearly and vividly the general physiography of the country, the distribution of forests, the climatic conditions, and chiefly the life–zones. The author admits four life-zones: the tropical, the subtropical, the temperate, and the Paramo zone, which is the treeless region above 11,000 feet to the snow line.