NOTE. 
Seven volumes, accompanied by one topographical and one geological 
atlas, embrace reports of Geographical Surveys West of the One hundredth 
Meridian, as follows: 
Volume I.—Geographical Eeport. 
Volume II.—^^Astronomy and Barometric Hypsometry. 
Volume III.—Geology and Mineralogy. 
Volume IV.—Paleontology. 
Volume V.—Zoology. 
Volume VI.—Botany. 
Volume VII. Ethnology, Philology, and Ruins. 
The Topographical Atlas edition, consisting of Title-Page, Legend, and 
Conventional Signs Sheets, Index, Progress and Basin Maps,;and Sheets 
Nos. 49, 50, 57, 58, 59, 65, 66, 67, 75, 76, 83, 61 (B), 69 (D), 61 (C), 61 (C 
sub), have been issued at date of sending forward the MS. of this volume. 
Other sheets will follow as rapidly as they can be prepared, engraved, and 
printed. 
Sheets 61 (B), 61 (C), and 69 (D) are projected upon a scale of 1 inch 
to 4 miles, while the scale of 1 inch to 2 miles has been used for Sheet 61 (C 
sub), the latter embracing a part of the San Juan Mining Region, South¬ 
western Colorado. 
Geological sheets, supplementing Volume III, based upon the topo¬ 
graphical results, are in an advanced stage of completion. 
Ill 
