EIGHTH ANNUAL REPORT. 207 
edge of the subjects treated and for the material placed at his disposal by 
them in the American Museum of Natural History, and also to William 
T. Hornaday, Director of the New York Zoological Park. 
Reference has been had to the following books: 
The Geography of Mammals, by W. L. and P. L. Sclater. 
Mammals Living and Extinct, by Flower and Lydekker. 
Geographic History of Mammals, by Lydekker. .. 
Mammalia, by F. E. Beddard. 
Distribution of Animals, by Angelo Heilprin. 
Island Life, by Alfred Russel Wallace. 
A Synopsis of the Mammals of North America, by Daniel Giraud Elliot. 
And especially: The Rise of the Mammalia in North America, The 
Law of Adaptive Radiation, in American Naturalist, 1902, The Faunal 
Relations of Europe and America, and Theory of the Successive Invasions 
of an African Fauna into Europe, New York Academy of Science, 1900, 
by Henry Fairfield Osborn. 
Classification of the Fresh-Water Tertiary, The Merycodus, Field 
Notes, etc., in the Bulletins of the American Museum of Natural History, 
by W. D. Matthew. 
Polar Climate in Time, by G. R. Wieland, in the American Journal of 
Science for December, 1903. 
Origin of the Primates, by J. L. Wortman, in the American Journal of 
Science for June, 1903. 
