PREFACE. IX 



stranger fauna of the Rocky Mountain Eocene has been first made 

 known ; through Marsh, also, the first American Cretaceous Birds 

 have been named, and the announcement has come of a Bird with 

 teeth in sockets, like some of the higher Reptiles. In addition, the 

 labors, among Invertebrates, of Hall, Meek, Billings, and others ; 

 among Fishes, of Newberry ; among fossil Plants, of Lesquereux 

 and Dawson, have greatly advanced these departments of American 

 paleontology. 



The discoveries abroad, also, have been many and important, though 

 of less marked character than the American, because the accessible 

 field had already been well explored. Large additions have been 

 made to the history of prehistoric Man ; and the frontispiece of this 

 volume, — engraved, by Mr. John Karst of New York, from the pho- 

 tograph accompanying the memoir of E. Riviere, — representing a 

 skeleton of an inhabitant of Southern Europe in the early Stone age, 

 just as it lay after being uncovered from the stalagmite of a cavern, 

 exemplifies one of the classes of facts which have been elucidated. Be- 

 sides, much new light has been thrown on the successional relations of 

 species, and also on the right methods of interpreting geological records. 

 One of the important onward steps has been due to the discovery of 

 Primordial fossils in the Cambrian rocks of Great Britain. It led at 

 once to the announcement that those Cambrian fossiliferous strata were 

 nothing but Primordial beds. And since they are, also, conformable 

 to the overlying Silurian, and differ from the latter only very sub- 

 ordinately in kinds of life, no good reason longer remains for making 

 the Cambrian a grand division of the geological series, distinct from 

 the Silurian. 



In the preparation of this edition, I am largely indebted to many 

 scientific friends : in the first place, to all workers in the department, 

 through the land, whose published results have made the edition a 

 necessity, and from whose works I have freely taken facts and con- 

 clusions, with due acknowledgment ; also, for personal aid, to the able 

 paleontologist, F. B. Meek, to whom the country owes a world of 

 gratitude for his labors ; to 0. C. Marsh, for facts connected with 

 the Vertebrate life of the American Cretaceous and Tertiary ; to A. 

 H. Worthen, Director of the Geological Survey of Illinois, from 

 whom the volume has received several of its illustrations ; to L. Les- 

 quereux, for information with regard to fossil plants ; to James 

 Hall, the eminent paleontologist of New York ; to J. S. Newberry, 

 Chief Geologist of the State of Ohio ; to A. Winchell, formerly 

 State Geologist of Michigan, and now Chancellor of the Syracuse 

 University ; to G. K. Gilbert, Geologist of the Explorations under G. 



