The Galena and Maqnoketa Series. — Sardeson. 367 
Cincinnati Shales and Limestone, T. C Chaniberlin (1877). Geology 
of Wisconsin, vol. II, p. 314. 
Cincinnati Group, Moses Strong (1877). Geology of Wisconsin, vol. 
II, p. 685. 
Hudson River (Cincinnati) Shales and Limestone, T. C. Chamberlin 
(1883). Geology of Wisconsin, vol. I, p. 170. 
Cincinnati Group, F. W. Sardeson (1892). Bulletin, Minnesota Acad- 
emy of Natural Sciences, vol. Ill, No. 3, p. 325. 
Cincinnati Limestones and Shales, C. W. Hall and F. W. Sardeson 
(1892). Bulletin. Geological Society of America, vol. Ill, p. 365. 
Maquoketa Shales, W J McGee (1891). 11th Annual Report, United 
States Geological Survey, p. .326. 
Maquoketa Shales, Chas. R. Keyes (1893). 1st Annual Report, Iowa 
Geological Survey, p. 14. 
Maquoketa Shales, W. H. Norton (1893). 2d Annual Report Iowa 
Geological Survey, p. 177, pars. 
The lower two-thirds of the Maquoketa have been some- 
times clearly described as Galena. 
Galena limestone, N. H. Winchell (1884). Geological and Natural 
History Survey of Minnesota, Final Report, vol. I, p. 290, 297. 
Galena limestone, N. H. Winchell (1888). Geological and Natural 
History Survey of Minnesota, Final Report, vol. II, p. 41. 
Galena. Samuel Calvin (1895). 4th Annual Report, Iowa Geological 
Survey p. 80. 92. 
Conclusion. 
The classification of the Galena and Maquoketa series is 
easily seen to be lacking in uniformity, both in respect to di- 
vision and to nomenclature throughout their extent. Accord- 
ing to strict rules of priority, essentially that classification 
which has been and is recognized in Wisconsin should be valid 
in all four states and all counties where the Galena and Ma- 
quoketa series are found. Indeed, that fact seems to have 
been nearly always recognized, or, at least for no other appa- 
rent reason, that nomenclature is used in classifications where 
even a different basis of subdivision is followed. 
There is, however, in each of the other classifications that 
are in the above diagram a basis of truth, and their deviations 
are founded upon existing characters, whose meaning ought 
to be expressed in any general uniform classification of these 
series. To the Wisconsin classification, which will need to be 
but little corrected, should be added data derived from the 
others, as well as some data not expressed in any. Practically 
