The relation of the different primary regions and their subdivions may be approximately indicated diagrammatically as follows: AUTHOR'S EDITION. COLLEGE DEPARTMENT OF THE INTERIOR. UNITED STATES GEOLOGICAL AND GEOGRAPHICAL SURVEY. F. V. HAYDEN, U. S. Geologist-in-Charge. DESCRIPTION OF A FOSSIL PASSERINE BIRD FROM THE INSECT-BEARING SHALES OF COLORADO. BY J. A. ALLEN. EXTRACTED FROM THE BULLETIN OF THE SURVEY, VOL. IV, No. 2, WASHINGTON, May 3, 1878. |