weeks] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1904. 23 
Beyer (S. W.) and 'Williams (I. A.). 
1. Technology of clays. 
Iowa Geol. Surv., vol. 14, pp. 29-318, 7 pis., 30 figs., 1904. 
Discusses the classification, origin, and properties of clays, and manufacture ot 
clay wares. 
2. The geology of clays. 
Iowa Geol. Surv., vol. 14, pp. 377-554, 22 pis., 41 figs., 1904. 
Describes in detail the occurrence by counties of clays in Iowa, and their 
geologic horizons. 
Bilgram, Hugo. 
1. Inclusions in quartz. 
Phila. Acad. Nat. Sci., vol. 55, p. 700, 1904. 
Bishop (Irving- P.). 
1. P>onomic geology of western New York. 
N. Y. State Mus., 56th Ann. Rept., pp. r42-r74, 2 pis., 1904. 
Gives notes on the occurrence of economic products, particularly building 
stone, clays, salt, natural gas, and petroleum. 
Blake (William P.). 
1. Gypsum deposits in Arizona. 
U. S. Geol. Surv., Bull. no. 223, pp. 100-101, 1904. 
Describes character and occurrence of gypsum deposits in Arizona. 
2. Superficial blackening- and discoloration of rocks, especially in des- 
ert regions. 
Am. Inst. Mg. Engrs., Trans. (Lake Superior meeting, September, 1904), 5 
pp., 1904 [advance separate]. 
Describes surficial blackening of rocks and discusses its origin. 
3. Copper ore and garnet in association. 
Am. Inst. Mg. Engrs., Trans., vol. 34, pp. 886-890, 1904. Mg. Sc Sci. Press, 
vol. 89, pp. 72-73, 1904. Mg. World, vol. 21, p. 175, 1904. 
Describes various occurrences of copper ore and garnet in association and dis- 
cusses their origin. 
4. Origin of pebble-covered plains in desert regions. 
Am. Inst. Mg. Engrs., Trans., vol. 34, pp. 161-162, 1904. 
See no. 85 of the Bibliography for 1903, U. S. Geol. Surv., Bull. no. 240. 
5. Tombstone [Arizona] and its mines. 
Am. Inst. Mg. Engrs., Trans., vol. 34, pp. 668-670, 1904. 
See no. 87 of the Bibliography for 1903, U. S. Geol. Surv., Bull. no. 240. 
6. Evidences of plication in the rocks of Cananea, Sonora [Arizona]. 
Am. Inst. Mg. Engrs., Trans. (Lake Superior meeting, September, 1904). 
Advance separate, 2 pp., 1904. Mg. Rep., vol. 50, pp. 586-587, 1904. 
Blakemore (William). 
1. Graham Island coal [British Columbia]. 
Eng. & Mg. Jour., vol. 78, p. 631, 1904. 
Describes the occurrence of workable coal beds. 
