190 
POPULAR SCIENCE REVIEW. 
this subject, and especially what has been done in France in carrying out 
works of reboisementy with a view to preventing and arresting the destructive 
consequences and effects of torrents, and the results which have followed. 
THE CRETACEOUS YERTEBRATA OF NORTH AMERICA.* 
T HIS volume is another valuable contribution to the Geological Survey of 
the Territories, under the direction of Dr. Hayden ; and, considering 
how much important and interesting matter, both geological and palaeonto- 
logical, has been brought out by the arduous and energetic labours of the 
Director and his able collaborators during the progress of the survey, we 
cannot but hope and wish that it may be as successfully continued, by 
receiving the liberal support of the Government, as heretofore ; not only 
that the geological nature of the district should be well known in its imme- 
diate economical bearings, as advancing the interest of the State, but that 
by the full publication of the details obtained, European geologists may be 
enabled to compare the lithological structure and palaeontological character 
of the American strata with those in other areas considered to be either 
contemporaneous or homotaxious with them, and thus arrive at a more 
enlarged knowledge of the different physical conditions and the distribution 
of life which obtained in different parts of the earth’s surface during the 
time assumed to belong to the same great 'geological period. In the latter 
direction the memoir on the Cretaceous Yertebrata, by Professor E. D. Cope, 
is very important, for palaeontology lies at the very foundation of geological 
science ; and, therefore, as a contribution towards the solution of the 
numerous problems involved in the geological structure of the Western 
Territories, as well as the unfolding of the ancient life, this work must be 
considered of the highest rank, and also forms a companion volume to that 
on the Cretaceous Flora by Professor Lesquereux, already noticed (“Pop. 
Scien. Rev.” vol. xiv. p. 411). 
Independently of its palaeontological value it may be commended as a 
work of art, for it is illustrated by nearly sixty well-executed plates, with 
explanations and descriptions, together with a synopsis of the known cre- 
taceous vetebrata of North America, which now amount to 253 species of 
birds, reptiles, and fishes. In this list is included numerous remains from the 
Fort Union beds, or lignite group, considered by Professor Cope to be of 
cretaceous age, but which are referred by other authors to the tertiary 
epoch or transition series of Hayden, from their containing a tertiary flora 
associated with a cretaceous fauna, thus inferring — in this area at least — there 
is no real physical break in the deposition of the sediments between the 
well-marked cretaceous and tertiary groups. With regard to the fishes of 
the Niobrara group, it is important and interesting to observe that nearly all 
*“ Report of the United States Geological Survey of the Territories.” 
F. Y. Hayden. Vol. ii. “ The Vertebrata of the Cretaceous Formations of 
the West.” By E. D. Cope. Washington, 1875. 
