REVIEWS. 41 
mounds in Ohio. He closes with a chapter on the *' ái aig us to the 
Antiquity of man on the two Hemispheres.” The remaining articles are 
* Descriptions of certain Stone and Copper meena sed by th 
Mound Builders,” J oster, L ** List of the Birds of Alaska, 
n : 
with Biographical Notes,” by W. H. Dall and H. M. Bannister. “O 
Additions to the Bird Fauna of North America, made by the Scientific 
Corps of the Russo-American Telegraph Expedition," by S. F. Baird, and 
“A preliminary List of the Butterflies of Iowa,” by S. H. Scudder 
zc 
EOLOGY OF THE MISSOURI RIVER VALLEY.* — This is the final report 
of the interesting series from the able hands of Drs. Meek and Hayden, 
which have been already eA in This Report also includes one 
made by Dr. Hines on a portion of the route, and another by Professor 
Newberry, on the peat ae and Tertiary plants, x dria reviewed in 
the NATURALIST. A careful perusal of the latter, and of Dr. Hayden's 
chapter on the Physical Geography of the region surveyed would give 
any of our readers new ideas with regard to their own country. The 
pins n phical errors in the work are numerous, since it was printed dur- 
g the absence of the author; who read no proof of it. The historical 
Hin tine tion reviews the labors of previous explorers, and contains in- 
teresting remarks with regard to maps. These are especially opportune 
attached to the present report. The colors are excellent and its size and 
variety of details gives one a very clear idea of the geological structure 
of the Great Missouri Valley. 
The ter on physical spam contains a resumé of the results of 
the barometrical profiles run by t ifferent western government expe- 
ne showing the bòiterit rise üf the country west of St. Louis, to the 
Rocky Mountains. Dr. Hayden regards the viole country 
ve of the Mississippi as a vast plateau, which was gradually elevated to 
its present height, the strain bursting the central axis of the plateau and 
he R 
Mountains. Dr. Hayden describes only two types of these mountains, 
those having a granite nucleus and regular outline, and those composed 
of erupted rocks, which ‘‘are very rugged in their spies e irregular 
in their trend." The author regards the Black Hills as an example of the 
regular type, and describes the stratified rocks as lying MK a nucleus, 
or kernel, of granite without a break or any unconformability on either 
side of the axis of elevation to the latest period of the Cretaceous for- 
mation." From these facts we draw the inference that prior to the ele- 
vation of the Black Hills, which must have occurred after the deposition 
of the Cretaceous rocks, all of these formations presented an unbroken 
continuity over the whole area occupied by these mountains. This is 
* Geological Report of the Exploration of the Yellowstone and Missouri Rivers 
Dr. F. V. Hayden, assistant bg the direction of Captain (now Lieut. m asd 
Brevet Brig. General) W. F. Raynolds. 1859-60. Washington, 1869. 8vo, pp. 1 
AMER. NATURALIST, VOL. IV. 
