372 Reviews — Hitchcock and Blake's Ma]) of the United States. 



Maine State, by Prof. C. H. Hitchcock. 



Massachusetts State, by Dr. E. Hitchcock. 



Minnesota State, by Eobt. D. Owen. 



Missouri State, by G. 0. Swallow, Dr. F. V. Hayden, F. B. Meek. 

 ■ Nebraska Territory, by E. Dale Owen, Dr. F. V. Hayden. 



New Hampshire State, by Prof. C. H. Hitchcock. 



New Jersey, by Prof. H. D. Eogers. 



New Mexico, by Dr. F. V. Hayden. 



New York State, by W. W. Mather, Dr. E. Emmons, L. Vanuxem, 

 and J. Hall. 



Ohio State, by Prof. J. S. Newberry. 



Pacific Eailway Eeports, by F. B. Meek and others. 



Pennsylvania, by Prof. H. D. Eogers. 



Eocky Mountains, by Dr. F. V. Hayden. 



South Carolina, by Oscar M. Lieber and M. Tuomey. 



Tennessee State, by J. M. Safford. 



Vermont, by Dr. E. Hitchcock and others. 



Wisconsin, by Eobt. Dale Owen. 



Wyoming, etc., by Dr. F. Y. Haj^den. 



The Yellowstone Eiver, by Dr. F. V. Hayden. 



Many of these State Surveys have published numerous volumes on 



the Geology and Palfeontology of their several States, accompanied 



by maps and sections and excellent plates of Fossils. 



The Survey of the State of New York (one of the oldest) has 



published twenty-one volumes, comprising the Natural History and 



Agriculture of the State. 



Illinois, Iowa, Indiana, California, and other States, have also 

 achieved wonderful and rapid results, as attested by their numerous 

 and recently published works, most of which will be found noticed 

 in the pages of the Geological Magazine. 



The present Map, compiled for the 9th Census, is based on the 

 Military Map of the United States, by permission of the Chief 

 Engineer, and exhibits the physical features so far as the lakes and 

 river-systems are concerned, and upon which the geological forma- 

 tions are coloured. 



One feature which has probably influenced to some extent the 

 direction of the great river-systems of America (as pointed out by 

 Dana) is the comparative development of the older and harder rocks 

 on the eastern and western sides of the Continent — and to which 

 probably its subtriangular form is due — the central area being 

 chiefly occupied by the Cretaceous and Tertiary rocks, although traces 

 of both these are found on the seaboard of the east and west coasts. 

 Although on a comparatively small scale (36 by 24 inches), the 

 coup d'oeil presents us with a fair notion of the geological features 

 of this vast and well-favoured country. To the geologist, as to the 

 public at large, the most important area to be noticed at this time is 

 that occupied by the Carboniferous system ; and if arguments were 

 needed to favour the old-established belief that the general move- 

 ment of peoj)les is in a westerly direction, and that the country of 

 the future is North America, let our American cousins point with 



