190 THE ZOOLOGIS!. 
NOTICES OF NEW BOOKS. 
The Birds of the Colorado Valley; a Repository of Scientific and 
Popular Information concerning North American Ornithology. 
By Euuiorr Covsgs. Part I. Passeres to Laniide. 
Washington: Government Printing Office. 
No other portion of the United States of equal area presents 
such varied surface conditions and such climatic extremes as the 
Valley of the Colorado. Bounded by mountain ranges of 
immense extent and elevation (the main chain of the Rocky 
Mountains on the east, the Sierra Nevadas on the west), the 
greater part of the country is low, hot, and arid. The 
temperature, rainfall, and course of the seasons in this region are 
alike remarkable, and so sensibly affect the animal and vegetable 
life that, as Dr. Hayden has expressed it, ‘‘ contiguous areas of 
insignificant extent may differ as much in their natural productions 
as if they stretched over many degrees of latitude.” 
This great valley takes in Arizona, much of New Mexico, 
Utah, and Nevada, a part of the state of Colorado, and some of 
Southern California. Although we have not been altogether 
without information as regards the zoology of portions of this 
territory, thanks to the labours of Mr. Cassin, Dr. Woodhouse, 
Dr. Heerman, Messrs. Kennerly, T. C. Henry, J. G. Cooper, and 
other explorers, such information has been but fragmentary, and 
published in scattered volumes which are not always readily 
accessible. It has devolved on Dr. Elliott Coues to bring 
together in a most convenient form a resumé of the investigations 
of these different naturalists, which he has supplemented with 
valuable additions of his own, derived from personal observations 
made by him in different parts of the territory referred to. 
To say that the work is thorough and exact in its nature, is 
to say no more than is applicable to all that emanates from the 
pen of Dr. Coues, who, combining the important qualifications of 
an observant field naturalist with an extensive acquaintance with 
the bibliography of his subject, is pre-eminently fitted to 
undertake the preparation of such a comprehensive treatise as 
that under consideration. 
In dealing with each species in succession, the plan which he 
