86 BIBLIOGRAPHY AND INDEX OF N. A. GEOLOGY, [bull. 162. 
737 Spencer (J. W.). Geological waterways across Central America. 
Pop. Sci. Mo., vol. liii, pp. 577-593, 9 figs., 1898. 
Describes the physiography of the region and discusses the evidences 
of former oceanic connections. 
738 Spencer (L. J.). Diaphorite from Montana and Mexico. 
Am. Jour. Sci., 4th ser., vol. vi, p. 316, 1898. 
Describes crystallographic characters of the material. Discusses 
relations with brongniardite. 
739 Spurr (Josiah Edward). Geology of the Yukon gold district, 
Alaska, with an introductory chapter on the history and 
condition of the district to 1897, by Harold Beach Goodrich. 
U. S. Geol. Surv., 18th Ann. Kept., Pt. Ill, pp. 101-392, pis. xxxii-li, 
figs. 7-25, 1898. 
Describes the occurrence, character, and distribution of the sedi- 
mentary and igneous rocks and of the auriferous veins and placer 
deposits of the region. Discusses the evidences of movement in the 
earth's crust. Includes a report by F. H. Knowlton on the fossil plants 
collected, and a chapter on recent warpings of the region, by H. B. Good- 
rich. 
739a Geology of the Aspen mining district, Colorado, with atlas. 
U. S. Geol. Surv., Mon. XXXI, 260 pp., pis. i-xliii, figs. 1-11, atlas 
sheets i-xxx, 1898. 
Describes the character and occurrence of the Cambrian, Silurian, 
Carboniferous, Jura- Trias, and Cretaceous sediments and the igneous 
rocks of the region. Includes description of the mines, a discussion of 
the character of the ores and ore deposition, and a discussion of fault 
phenomena. 
740 Squier (G. H.). Studies in the driftless region of Wisconsin, II. 
Jour, of Geol., vol. vi, pp. 182-192, figs. 3-7, 1898. 
Describes occurrence and formation of beds of nonglacial origin. 
See Bibliography and Index for 1897, No. 577, for notice of first paper. 
741 Stanton (Timothy W.). Memoir of Joseph Francis James. 
Geol. Soc. Am., Bull., vol. ix, pp. 408-411, 1898. 
Gives a sketch of the life and scientific work of Professor James and 
includes a list of his published papers. 
742 The Mesozoic section of Sierra Blanca, Texas. 
Science, new ser., vol. vii, p. 429 (i p.), 1898. 
Contains summary of paper read before the Geological Society of 
Washington. 
743 Stevenson (John J.). Notes on the geology of the Bermudas. 
N. Y. Acad. Sci., Trans., vol. xvi., pp. 96-124, pis. viii-x, 1898. 
Describes the materials forming the surface of the islands and the 
relations of the land and submerged area. Discusses the literature on 
the geologic history of the Bermudas. 
744 [Geology and its relations to topography.] 
Am. Soc. Civil Engrs., Trans., vol. xxxix, pp. 88-90, 1898. 
In discussion of paper by John C. Branner on the same subject. 
