20 BIBLIOGRAPHY AND INDEX OF N. A. GEOLOGY, [bull. 162. 
51 Barrell (R. W.). Gold mining in Oregon. 
Mines and Minerals, vol. xix, pp. 12-15, 5 figs., 1898. 
Describes the topographic features of eastern Oregon and the occur- 
rence of gold. 
52 Bascom (Florence). [Review of u Maryland Geological Survey, 
vol. i, 1897."] 
Am. Geol., vol. xxii, pp. 375-377, 1898. 
53 See Diller (J. S.), No. 234. 
54 Bather (F. A.). Wachsmuth and Springer's classification of crinoids. 
Nat. Sci., vol. xii, pp. 337-345, 1898. 
55 Bayley (W. S.). See Diller (J. S.), No. 234. 
56 Becker (George F.). Reconnaissance of the gold fields of southern 
Alaska, with some notes on general geology. 
U. S. Geol. Surv., 18th Ann. Kept., Pt. Ill, pp. 7-86, pis. i-xxxi, figs. 1-6, 
1898. 
Includes notes on some igneous rocks and on the glacial features and 
volcanic phenomena of the region. Describes the occurrence and char- 
acter of the auriferous deposits and veins. 
57 The Witwatersrand banket, with notes on other gold-bearing 
pudding stones. 
U. S. Geol. Surv., 18th Ann. Rept., Pt. V, pp. 153-184, 1 fig.; Review 
Zeit. fur prak. Geol., Heft 6, pp. 212-217, 1898. 
Includes notes on auriferous conglomerates occurring in the United 
States. 
58 Auriferous conglomerates of the Transvaal. 
Am. Jour. Sci., 4th ser., vol. v, pp. 193-208, 1898. 
In describing the character of the conglomerates and the origin of 
gold, refers to the river gravels and beach sands of California. 
59 On the determination of plagioclase feldspars in rock sections. 
Am. Jour. Sci., 4th ser., vol. v, pp. 349-354, pi. iii, 1898. 
Reviews Michel-Levy's method of determining plagioclase feldspars. 
60 Beecher (Charles E.). Origin and significance of spines. A study 
in evolution. 
Am. Jour. Sci., 4th ser., vol. vi, pp. 1-20, pi. i, figs. 1-31; 125-136; 249- 
268, figs. 32-50; 329-359, figs. 51-73, 1898. 
Discusses the origin, growth, development, and significance of 
spines. Includes a bibliography of the subject. 
61 Beede (J. W.). New corals from the Kansas Carboniferous. 
Kan. Univ. Quart., vol. vii, pp. 16-18, 1898. 
Describes four new species. 
62 Variations of external appearance and internal characters of 
Spirifer cameratus Morton. 
Kan. Univ. Quart., vol. vii, pp. 103-105, pi. vi, fig. 1-3, 1898. 
