TABLE OF CONTENTS. 



PALEONTOLOGY. 



Report of Leo Lesquereux 271 



Letter to Dr. Hayden 273 



On the Tertiary flora of the North American Lignitic, considered as evi- 

 dence of the age of the formation 275 



Table of subdivisions of the Tertiary of Europe, according to the floras 284 



Table exposing the relation of the fossil plants of Point of Rocks 286 



Description of species of fossil plants from Point of Rocks 296 



New species of Tertiary fossil plan ts briefly described 308 



A review of the Cretaceous flora of North America 316 



§ 1. General remarks _ 316 



§ 2. Description and enumeration of generic and specific divisions 333 



ARCHEOLOGY. 



Report of W. H. Jackson.... 367 



Ancient ruins in Southwestern Colorado 369 



ZOOLOGY. 



Report of Ernest Ingersoll , 383 



Natural history, 1874 , 385 



Letter to Dr. F. V. Hayden 385 



List of localities of specimens 386 



General account of the work 387 



Special report on the Mollusca * 389 



List of authorities 407 



TOPOGRAPHY AND GEOGRAPHY. 



Reports of Henry Gannett, S. B. Ladd, and A. D. Wilson. 



Report of Henry Gannett, M. E 413 



Introductory letter 413 



Chapter I 415 



Previous explorations in the district 415 



Geography of the district 416 



Height of the walls of the Grand Canon of the Gunnison 426 



Distribution of vegetation 428 



Settlements, trails, roads, etc 428 



Chapter II. Elevations 429 



Revision of the heights of summits in the Sawatch and Elk systems -. . 429 



Elk Mountains 430 



On the plateau 432 



Report of S. B. Ladd, M. E., northern division = 435 



Letter to Dr. F. V. Hayden. 435 



Report 435 



Roads and trails 439 



List of elevations. : 441 



Report of A. D. Wilson - 443 



Means of communication between Denver and the San Juan mines 443 



Comparisons of aneroids with the mercurial barometer 447 



Report of Franklin Rhoda «,<..„ 451 



Topography of the San Juan country 451 



Ascent of Mount Sneffels 479 



Methods used in determining the elevation of points in the district 488 



Notes useful for the location of miners' monuments in Baker's Park 496 



General index 497 



Systematic index 509 



LIST OF NEW SPECIES DESCRIBED. 



FOSSIL PLANTS. 



Fucus lignitum a , 290 



Salviaia attenuata 296 



Selagmella? falcata 297 



laciniata 297 



Sequoia biformis -' 298 



