LETTER OF TRANSMITTAL. 
United States Engineer Office, 
Geographical Explorations and Surveys 
West of the One hundredth Meridian, 
Wasliwgton^ D. C., December 15, 1875. 
General : I have the honor to submit herewith a report, in two jJfirts, 
upon the paleontological results arising from the collections and examina¬ 
tions made during the years 1871, 1872, 1873, 1874, and 1875, in connec¬ 
tion with geographical explorations and surveys west of the one hundredth 
meridian, for publication as Volume IV of the reports authorized by acts 
of Congress approved June 23, 1874, and February 15, 1875.' 
Part I is by Dr. C. A. White, on the collection of invertebrate fossils, 
numbering one hundred and eighty-three distinct species, of which fifty 
are new to science. 
A preliminary report, with descriptions of new species, by the same 
author, was, with your sanction, published in December, 1874, the sub¬ 
stance of which is embodied in the present volume. 
The attainments and the experience of Dr. White in this branch of 
science are a guarantee that his work has been well done. 
Part II is comprised of a similar treatment of the vertebrate fossil col¬ 
lections, by Prof. E. D. Cope, who has given to this subject years of study. 
Professor Cope was connected with the expedition during the season of 
1874, in which he made collections himself, and, in addition, was enabled to 
prosecute geological researches. A portion of his results were published in 
preliminary form in a “Report upjon the Vertebrate Fossils discovered in 
New Mexico, with description of new Species,” November 28, 1874; and a 
“ Systematic Catalogue of the Vertebrata of the Eocene of New^ Mexico, 
collected in 1874,” April 17, 1875. His geological deductions appear in my 
anniml report. Appendix LL, Annual Report of the Chief of Engineers, 1875, 
