IV ADVERTISEMENT. 
28. The Gabbros and Associated Hornblende Rocks occurring in the Neighborhood of Baltimore, 
Maryland, by George Huntington Williams. 1886. 8°. 78 pp. 4 pi. Price 10 cents. 
29. On the Fresh- Water Invertebrates of the North American Jurassic, by Charles A. White. 1886. 
8°. 41pp. 4 pi. Price 5 cents. 
30. Second Contribution to the Studies on the Cambrian Faunas of North America, by Charles Doo- 
little Walcott. 1886. 8°. 369 pp. 33 pi. Price 25 cents. 
31. Systematic Review of our Present Knowledge of Fossil Insects, including Myriapods and Arach- 
nids, by Samuel Hubbard Scudder. 1886. 8°. 128 pp. Price 15 cents. 
32. Lists and Analyses of the Mineral Springs of the United States (a Preliminary Study), by Albert 
C.Peale. 1886. 8°. 235 pp. Price 20 cents. 
33. Notes on the Geology of Northern California, by J. S. Diller. 1886. 8°. 23 pp. Price 5 cents. 
34. On the Relation of the Laramie Molluscan Fauna to that of the Succeeding Fresh-Water Eocene 
and Other Groups, by Charles A. White. 1886. 8°. 54 pp. 5 pi. Price 10 cents. 
35. Physical Properties of the Iron -Carburets, by Carl Barus and Vincent Strouhal. 1886. 8°. 62 
pp. Price 10 cents. 
36. Subsidence of Fine Solid Particles in Liquids, by Carl Barns. 1886. 8°. 58 pp. Price 10 cents. 
37. Types of the Laramie Flora, by Lester F. Ward. 1887. 8°. 354 pp. 57 pi. Price 25 cents. 
38. Peridotite of Elliott County, Kentucky, by J. S. Diller. 1887. 8°. 31 pp. 1 pi. Price 5 cents. 
39. The Upper Beaches and Deltas of the Glacial Lake Agassiz, by Warren Upham. 1887. 8°. 84 
pp. 1 pi. Price 10 cents. 
40. Changes in River Courses in Washington Territory due to Glaciation, by Bailey Willis. 1887. 
8°. 10 pp. 4 pi. Price 5 cents. 
41. On the Fossil Faunas of the Upper Devonian — the Genesee Section, New York, by Henry S. 
Williams. 1887. 8°. 121pp. 4 pi. Price 15 cents. 
42. Report of Work done in the Division of Chemistry and Physics, mainly during the Fiscal Year 
1885-'86. F. W. Clarke, Chief Chemist. 1887. 8°. 152 pp. 1 pi. Price 15 cents. 
43. Tertiary and Cretaceous Strata of the Tuscaloosa, Tombigbee, and Alabama Rivers, by Eugene 
A. Smith and Lawrence C. Johnson. 1887. 8°. 189 pp. 21 pi. Price 15 cents. 
44. Bibliography of North American Geology for 1886, by Nelson H. Darton. 1887. 8°. 35 pp. 
Price 5 cents. 
45. The Present Condition of Knowledge of the Geology of Texas, by Robert T. Hill. 1887. 8°. 94 
pp. Price 10 cents. 
46. Nature and Origin of Deposits of Phosphate of Lime, by R. A. F. Penrose, jr., with an Intro- 
duction by N. S Shaler. 1888. 8°. 143 pp. Price 15 cents. 
47. Analyses of Waters of the Yellowstone National Park, with an Account of the Methods of 
Analysis employed, by Frank Austin Gooch and James Edward Whitfield. 1888. 8°. 84 pp. Price 
10 cents. 
48. On the Form and Position of the Sea Level, by Robert Simpson Woodward. 1888. 8°. 88 pp. 
Price 10 cents. 
49. Latitudes and Longitudes of Certain Points in Missouri, Kansas, and New Mexico, by Robert 
Simpson Woodward. 1889. 8°. 133 pp. Price 15 cents. 
50. Formulas and Tables to facilitate the Construction and Use of Maps, by Robert Simpson Wood- 
ward. 1889. 8°. 124 pp. Price 15 cents. 
51. On Invertebrate Fossils from the Pacific Coast, by Charles Abiathar White. 1889. 8°. 102 pp. 
j4pl. Price 15 cents. 
52. Subaerial Decay of Rocks and Origin of the Red Color of Certain Formations, by Israel Cook 
Russell. 1889. 8°. 65 pp. 5 pi. Price 10 cents. 
53. The Geology of Nantucket, by Nathaniel Southgate Shaler. 1889. 8°. 55 pp. 10 pi. Price 10 
cents. 
54. On the Thermo-Electric Measurement of High Temperatures, by Carl Barus. 1889. 8°. 313 pp. 
incl. 1 pi. 11 pi. Price 25 cents. 
55. Report of Work done in the Division of Chemistry and Physics, mainly during the Fiscal Year 
1886-'87. Frank Wigglesworth Clarke, Chief Chemist. 1889. 8°. 96 pp. Price 10 cents. 
56. Fossil Wood and Lignite of the Potomac Formation, by Frank Hall Knowlton. 1889. 8°. 72 pp. 
7 pi. Price 10 cents. 
57. A Geological Reconnaissance in Southwestern Kansas, by Robert Hay. 1890. 8°. 49 pp. 2 pi. 
Price 5 cents. 
58. The Glacial Boundary in Western Pennsylvania, Ohio, Kentucky, Indiana, and Illinois, by George 
Frederick Wright, with an Introduction by Thomas Chrowder Chamberlin. 1890. 8°. 112 pp. 8 pi. 
Price 15 cents. 
59. The Gabbros and Associated Rocks in Delaware, by Frederick D. Chester. 1890. 8°. 45 pp. 
] pi. Price 10 cents. 
60. Report of Work done in the Division of Chemistry and Physics, mainly during the Fiscal Year 
1887-88. F. W. Clarke, Chief Chemist. 1890. 8°. 174 pp. Price 15 cents. 
61. Contributions to the Mineralogy of the Pacific Coast, by William Harlow Melville and Waldemar 
Lindgren. 1890. 8°. 40 pp. 3 pi. Price 5 cents. 
62. The Greenstone Schist Areas of the Menominee and Marquette Regions of Michigan; a Contri- 
