170 BIBLIOGRAPHY OP NORTH AMERICAN GEOLOGY, 1906-1907. 
Sherzer, William H. 
2197. Glacial notes from the Canadian Rockies and Selkirks. — Science, new 
sei\, vol. 23, pp. 351-354, March 2, 1906. 
Describes the condition of various glaciers. 
2197a. Glaciers of the Canadian Rockies and Selkirks. — Smithsonian Contr. 
to Knowledge, vol. 34, xii, 135 pp., 42 pis., 1907. 
2198. The Lefroy, a parasitic glacier. — Abstract: Geol. Soc. America, BuU., 
vol. IT, pp. 707-708, 1907. 
2199. Origin of the massive block moraines in the Canadian Rockies and 
Selkirks. — Abstract: Geol. Soc. America, Bull., vol. 17, p. 708, 1907. 
Shimek, B. 
2200. The loess and associated interglacial deposits. — Abstract: Geol. Soc. 
America, Bull., vol. 16, p. 589, 1906. 
2201. The loess of the Missouri River. — Iowa Acad. Sci., Proa, vol. 14, 
pp. 237-256, 6 figs., 1907. 
Discusses the origin of the loess, particularly the shells of the terrestrial mollusks in 
the loess. 
Shinier, Hervey Woodburn. 
2202. Old age in Brachiopoda, a preliminary study. — Am. Naturalist, vol. 
40, pp. 95-121, 30 figs., February, 1906. Abstract: Science, new ser., vol. 23, 
p. 290, February 23, 1906 ; Am. Assoc. Adv. Sci., Proa, vol. 55, p. 379, 1906. 
Describes and illustrates the characters which mark old age in brachiopods. 
2203. An almost complete specimen of Strenuella strenua (Billings). — Am. 
Jour. Sci., 4th ser., vol. 23, pp. 199-201, 3 figs., March, 1907. 
Describes a specimen of the trilobite Strenuella strenua from the lower Cambrian 
slates of Massachusetts. 
2204. A lower-middle Cambrian transition fauna from Braintree, Mass. — 
Am. Jour. Sci., 4th ser., vol. 24, pp. 176-178, 1 fig., August, 1907. 
2205. The broader features of the geologic history of North America in 
diagram.— Tech. Quart., vol. 20, no. 3, pp. 287-291, 1 fig., September, 1907. 
North American index fossils. — See Grabau and Shinier, nos. 1005, 1006. 
Siebenthal, C. E. 
2206. Alluvial slopes. — Science, new ser., vol. 23, pp. 748-749, May 11, 1906. 
2207. Gypsum of the Uncompahgre region, Colorado. — U. S. Geol. Survey, 
Bull. no. 285, pp. 401-403, 1 fig., 1906. 
Describes the general geology and the occurrence and relations of the gypsum beds. 
2208. Gypsum deposits of the Laramie district, Wyoming. — U. S. Geol. Sur- 
vey, Bull. no. 285, pp. 404-405, 1906. 
Describes the occurrence and character of deposits of rock gypsum and gypsite. 
2209. Bentonite of the Laramie basin, Wyoming. — U. S. Geol. Survey, Bull, 
no. 285, pp. 445-447, 1906. 
Describes the physical characters, composition, and uses of the clay and the geologic 
occurrence and distribution of the deposits. 
2210. Notes on glaciation in the Sangre de Cristo Range, Colorado. — Jour. 
Geology, vol. 15, no. 1, pp. 15-22, 6 figs., 1907. 
Describes various evidence of glaciation in the Sangre de Cristo Range and shows 
that the morainic remains indicate two periods of glaciation. 
2211. Coal of Laramie basin, Wyoming. — U. S. Geol. Survey, Bull. no. 316, 
pp. 261-263, 1907. 
Description of the Joplin district.— See Smith and Siebenthal, no. 2251. 
