weeks] PALEONTOLOGY, PETROLOGY, AND MINERALOGY, 1894. 87 
524 Smyth (C. H., jr.). On gabbros in the southwestern Adirondack 
region [New York]. 
Am. Jour. Sci., 3d ser., vol. xlviii, pp. 54-65. 
Describes the petrographic characters of the gabbf o of the southwest 
corner of Hamilton County and the contact of the gabbro and gneiss. 
525 A group of diabase dikes among the Thousand Islands, St. 
Lawrence River. 
N. Y. Acad. Sci., Trans., vol. xiii, pp. 209-214. 
Describes the occurrence of the dikes and the microscopic character 
of the dike rocks. 
526 Keport on a preliminary examination of the general and 
economic geology of four townships in St. Lawrence and 
Jefferson counties [N. Y.|. 
N. Y. State Mus., 47th Ann. Rept., pp. 687-709, with map. 
Describes the character of the crystalline and sedimentary rocks of 
the region, and discusses the evidences as to their stratigraphic rela- 
tions. Discusses the evidences as to the origin of the iron ores of the 
region, aud describes the talc and marble industries. 
527 On a basic rock derived from granite. 
Jour, of Geol., vol. ii, pp. 667-679. 
Abstract: Am. Geol., vol. xiv, p. 195 (10 1.). 
Describes the character and origin of the rock and the microscopic 
and chemical characteristics of the alteration product occurring in 
hematite deposits of Jefferson County, N. Y. 
528 Smyth (Henry Lloyd). Relations of the Lower Menominee and 
Lower Marquette series in Michigan (preliminary). 
Am. Jour. Sci., 3d ser., vol. xlvii, pp. 216-223. 
Abstract: Am. Geo]., vol. xiii, p. 359 (i p.). 
Describes the lithologic characters and succession of these two 
series, discusses their structure and distribution, and gives a summary 
of conclusions. 
529 The quartzite tongue at Republic, Mich. 
Jour, of Geol., vol. ii, pp. 680-691, figs. 1-5. 
Describes the geologic structure of the region and the characteris- 
tics of the quartzite and jasper tongues that extend from the main 
mass of quartzite. 
530 Spencer (Arthur C). Occurrence in Iowa of fossiliferous concre- 
tions similar to those of Mazon Creek. 
Iowa Acad. Sci., Proc, vol. i, pt. iv, p. 55. 
Describes the occurrence of plant remains in the Carboniferous of 
Iowa. 
531 Spencer (Joseph W.). Deformation of the Luudy Beach and birth 
of Lake Erie. 
Am. Jour. Sci., 3d ser., vol. xlvii, pp. 207-212. 
Describes the formation of Lundy Beach and its eifect on the drain- 
ago of the Great Lakes and gives an estimate of the rate of uplift in 
the Niagara district. 
