SERIES M--GENERAL HYDROGRAPHIC INVESTIGATIONS. WS 56. Methods of stream measurement. 1901. 51 pp., 12 pls. WS 64. Accuracy of stream measurements, by E. C. Murphy. 1902. 99 pp., 4 pls. WS 76. Observations on the flow of rivers in the vicinity of New York City, by H. A. Pressey. 1902. 108 pp., 13 pls. WS 80. The relation of rainfall to run-off, by G. W. Rafter. 1903. 104 pp. WS 81. California hydrography, by J. B. Lippincott. 1903. 488 pp., 1 pl. WS 88. The Passaic flood of 1902, by G. B. Hollister and M. O. Leighton. 1903. 56 pp., 15 pls. WS 91. Natural features and economic development of the Sandusky, Maumee, Muskingum, and Miami drainage areas in Ohio, by B. H. Flynn and M. S. Flynn. 1904.--pp. WS 92. The Passaic flood of 1903, by M. O. Leighton. 1904.--pp., 7 pls. SERIES N--WATER POWER. WS 24. Water resources of State of New York, Pt. I, by G. W. Rafter. 1899. 92 pp., 13 pls. WS 25. Water resources of State of New York, Pt. II, by G. W. Rafter. 1899. 100-200 pp., 12 pls. WS 44. Profiles of rivers, by Henry Gannett. 1901. 100 pp., 11 pls. WS 62. Hydrography of the Southern Appalachian Mountain region, Pt. I, by H. A. Pressey. 1902. 95 pp., 25 pls. WS 63. Hydrography of the Southern Appalachian Mountain region, Pt. II, by H. A. Pressey. 1902. 96-190 pp., 26-44 pls. WS 69. Water powers of the State of Maine, by H. A. Pressey. 1902. 124 pp., 14 pls. SERIES O--UNDERGROUND WATERS. WS 4. A reconnaissance in southeastern Washington, by I. C. Russell. 1897. 96 pp., 7 pls. WS 6. Underground waters of southwestern Kansas, by Erasmus Haworth. 1897. 65 pp., 12 pls. WS 7. Seepage waters of northern Utah, by Samuel Fortier. 1897. 50 pp., 3 pls. WS 12. Underground waters of southeastern Nebraska, by N. H. Darton. 1898. 56 pp., 21 pls. WS 21. Wells of northern Indiana, by Frank Leverett. 1899. 82 pp., 2 pls. WS 26. Wells of southern Indiana (continuation of No. 21), by Frank Leverett. 1899. 64 pp. WS 30. Water resources of the lower peninsula of Michigan, by A. C. Lane. 1899. 97 pp., 7 pls. WS 31. Lower Michigan mineral waters, by A. C. Lane. 1899. 97 pp., 4 pls. WS 34. Geology and water resources of a portion of southeastern South Dakota, by J. E. Todd. 1900. 34 pp., 19 pls. WS 53. Geology and water resources of Nez Perces County, Idaho, Pt. I, by I. C. Russell. 1901. 86 pp., 10 pls. WS 54. Geology and water resources of Nez Perces County, Idaho, Pt. II, by I. C. Russell. 1901. 87-141 pp. WS 55. Geology and water resources of a portion of Yakima County, Wash., by G. O. Smith. 1901. 68 pp., 7 pls. WS 57. Preliminary list of deep borings in the United States, Pt. I, by N. H. Darton. 1902. 60 pp.