II ADVERTISEMENT. 
XVII. Seventeenth Annual Eeport of the United States Geological Survey, 1895-'96, Charles D, 
Walcott, Director. 1896. 8°. 3 pt. in 4 vol. xxii, 1076 pp., 67 pi. and maps ; xxv, 864 pp., 113 pi. and 
maps; xxiii, 542 pp., 8 pi. and maps; iii, 543-1058 pp., 9-13 pi. 
XVIII. Eighteenth Annual Report of the United States Geological Survey, 1896-97, Charles D. 
Walcott, Director. 1897. (Parts II a.id III, 1898.) 8°. 5 pt, in 6 vol. 440 pp., 4 pi. and maps; v, 653pp., 
105 pi. and maps ; v, 861 pp., 118 pi. and maps; x, 756pp., 102 pi. and maps ; xii, 642 pp., 1 pi. ; 643-1400 pp. 
XIX. Nineteenth Annual Report of the United States Geological Survey, 1897-'98, Charles D. 
Walcott, Director. 1898. (Parts II, III, and V, 1899.) 8°. 6 pt. in 7 vol. 422 pp., 2 maps ; v, 958 pp., 
172 pi. and maps; v, 785 pp., 99 pi. and maps; viii, 814 pp., 118 pi. and maps; xvii, 400 pp., 110 pi. and 
maps ; viii, 651 pp., 11 pi. ; viii, 706 pp. 
XX. Twentieth Annual Report of the United States Geological Survey, 1898-'99, Charles D. Wal- 
cott, Director. 1899. 8°. 7 pt. in 8 vol. 551 pp., 2 pi.; v, 953 pp., 193 pi. and maps; v, 595 pp., 78 pi. 
and maps; vii, 660 pp., 75 pi. and maps; xix, 498 pp., 159 pi. and maps; viii, 616 pp. ; xi, 804 pp., 1 pi.; 
v, 509 pp., 38 pi. and maps. 
MONOGRAPHS. 
I. Lake Bonneville, hy Grove Karl Gilbert. 1890. 4°. xx, 438 pp. 51 pi. 1 map. Price $1.50. 
II. Tertiary History of the Grand Canon District, with Atlas, hy Clarence E. Dutton, Capt., U. S. A. 
1882. 4°. xiv, 264 pp. 42 pi. and atlas of 24 sheets folio. Price $10.00. 
III. Geology of the Comstock Lode and the Washoe District, with Atlas, by George F. Becker. 1882. 
4°. xv, 422 pp. 7 pi. and atlas of 21 sheets folio. Price $11.00. 
IV. Comstock Mining and Miners, by Eliot Lord. 1883. 4°. xiv, 451 pp. 3 pi. Price $1.50. 
V. The Copper-Bearing Rocks of Lake Superior, by Roland Duer Irving. 1883. 4°. xvi, 464 pp. 
15 1. 29 pi. and maps. Price $1.85. 
VI. Contributions to the Knowledge of the Older Mesozoic Flora of Virginia, by William Morris 
Fontaine. 1883. 4°. xi, 144 pp. 54 1. 54 pi. Price $1.05. 
VII. Silver-Lead Deposits of Eureka, Nevada, by Joseph Story Curtis. 1884. 4°. xiii, 200 pp. 16 
pi. Price $1.20. 
VIII. Paleontology of the Eureka District, by Charles Doolittle Walcott. 1884. 4°. xiii, 298 pp. 
24 1. 24 pi. Price $1.10. 
IX. Brachiopoda and Lamellibranchiata of the Raritan Clays and Greensand Marls of New Jersey, 
by Robert P. Whitfield. 1885. 4°. xx,338pp. 35 pi. 1 map. Price $1.15. 
X. Dinocerata. A Monograph of an Extinct Order of Gigantic Mammals, by Othniel Charles Marsh. 
1886. 4°. xviii,243pp. 56 1. 56 pi. Price $2.70. 
XI. Geological History of Lake Lahontan, a Quaternary Lake of Northwestern Nevada, by Israel 
Cook Russell. 1885. 4°. xiv, 288 pp. 46 pi. and maps. Price $1.75. 
XII. Geology and Mining Industry of Leadville, Colorado, with Atlas, by Samuel Franklin Emmons. 
1886. 4°. xxix, 770 pp. 45 pi. and atlas of 35 sheets folio. Price $8.40. 
XIII. Geology of the Quicksilver Deposits of the Pacific Slope, with Atlas, by George F. Becker. 
1888. 4°. xix, 480 pp. 7 pi. and atlas of 14 sheets folio. Price $2.00. 
XIV. Fossil Fishes and Fossil Plants of the Triassic Rocks of New Jersey and the Connecticut Val- 
ley, by John S. Newberry. 1888. 4°. xiv, 152 pp. 26 pi. Price $1.00. 
XV. The Potomac or Younger Mesozoic Flora, by William Morris Fontaine. 1889. 4°. xiv, 377 
pp. 180 pi. Text and plates bound separately. Price $2.50. 
XVI. The Paleozoic Fishes of North America, by John Strong Newberry. 1889. 4°. 340 pp. 53 pi. 
Price $1.00. 
XVII. The Flora of the Dakota Group, a Posthumous Work, by Leo Lesquereux. Edited by F. H. 
Knowlton. 1891. 4°. 400 pp. 66 pi. Price $1.10. 
XVIII. Gasteropoda and Cephalopoda of the Raritan Clays and Greensand Marls of New Jersey, 
by Robert P. Whitfield. 1891. 4°. 402 pp. 50 pi. Price $1.00. 
XIX. The Penokee Iron-Bearing Series of Northern Wisconsin and Michigan, by Roland D. Irving 
and C. R. Van Hise. 1892. 4°. xix, 534 pp. 37 pi. Price $1.70. 
XX. Geology of the Eureka District, Nevada, with Atlas, by Arnold Hague. 1892. 4°. xvii, 419 pp. 
8 pi. Price $5.25. 
XXI. The Tertiary Rhynchophorous Coleoptera of North America, by Samuel Hubbard Scudder. 
1893. 4°. xi, 206 pp. 18 pi. Price 90 cents. 
XXII. A Manual of Topographic Methods, by Henry Gannett, Chief Topographer. 1893. 4°. xiv, 
300 pp. 18 pi. Price $1.00. 
XXIII. Geology of the Green Mountains in Massachusetts, by Raphael Pumpelly, J. E. Wolff, 
and T. Nelson Dale. 1894. 4°. xiv, 206 pp. 23 pi. Price $1.30. 
XXIV. Molluscaand Crustacea]of the Miocene Formations of New Jersey, by Robert Parr Whitfield. 
1894. 4°. 195 pp. 24 pi. Price 90 cents. 
XXV. The Glacial Lake Agassiz, by Warren Upham. 1895. 4°. xxiv, 658 pp. 38 pi. Price $1.70. 
XXVI. Flora of the Amboy Clays, by John Strong Newberry ; a Posthumous Work, edited by 
Arthur Hollick. 1895. 4°. 260 pp. 58 pi. Price $1.00. 
XXVII. Geology of the Denver Basin, Colorado, by S. F. Emmons, Whitman Cross, and George H. 
Eldridge. 1896. 4°. 556 pp. 31 pi. Price $1.50. 
