860 T]ie American Geohxjist. December, 1896 
GALENA SERIES. 
Lower Cliff limestone or lead-bearing limestone, D. D. Owen, (184i). 
Rep. on Exploration of Iowa, Wisconsin, and Illinois: p. 32. 
Chazy, Birds-eye, and Trenton limestones (undivided), Charles Whit- 
tlesey (1851). Geology of Lake Superior, Land District: p. 175. 
Trenton limestone group, James Hall (1861). Geology of Wisconsin, 
vol. I, p. .31. 
Trenton Group, A. H. Worthen (1866). Geological Survey of Illinois, 
rep. vol. I, p. 141. 
Trenton Group, C. A. White, (1870). Geology of Iowa. vol. i, p. 174. 
Trenton Limestone, Frank H. Bradley, (1870). Geological Survey of 
Illinois, vol. iv, p. 201. 
Trenton Limestones, James Shaw. (187.3). Geological Survey of Illi- 
nois, rep. vol. V, p. 66: Trenton formation, loc. cit., p. 86: Trenton 
Group, loc, cit., p. 111. 
Trenton limestone, A. H. Worthen, (1873). Geological Survey of Il- 
linois, rep. vol. V, p. 279. 
Trenton Group, C Rominger, (1873). Geological Survey of Michigan, 
rep. vol. I, part iii, p. 56. 
Trenton Limestone, N. H. Winchell, (1876). Fourth Annual Report 
Geological and Natural History Survey of Minnesota, p. 42. 
Trenton Group, T.C. Chamberlin, (1877). Geology of Wisconsin, vol. 
II, p. 290. 
Trenton limestone, A. H. Worthen, (1883). Geological Survey of Il- 
linois, rep. vol. VII, p. 40. 
Rocks of the Trenton Period, N. H. Winchell, (1884). Geological and 
Natural History Survey of Minnesota, Final Report, vol. i, p. (249) 339. 
Rocks of the Trenton Period (part), N. H. Winchell, (1888). Geologi- 
cal and Natural History Survey of Minnesota, Final Report, vol. ii, p. 39. 
Trenton Group, F. W. Sardeson, (1892). Bulletin Minnesota Acad- 
emy of Natural Sciences, vol. iii, p. 325. 
Trenton limestones and shales, C. W. Hall and F. W. Sardeson (1892). 
Bulletin of the Geological Society of America, vol. in, p. 356. 
Galena-Trenton limestones. W. H. Norton, (1893). Iowa Geological 
Survey Ann. Rep., vol. ii, p. 178. 
Trenton, Samuel Calvin (1895). Iowa, etc., vol. 4, pp. 7.3, 91. 
Divisions of this Galena series have been made with consid- 
erable variation by different authors in ditferent states. But 
the division line v^^hich has been most uniforml}'^ followed is 
that between the "Trenton" or Lower Trenton and the Gale- 
na. The latter formation rather than the former is probably 
equivalent to the Trenton limestone of New York. Confusion 
will be avoided therefore, by using a new local term, Beloit 
formation, and the local term Galena for these two divisions. 
