HISTORICAL GEOLOGY 85 



plants to be described and illustrated were also from 

 Ohio, in an article by Ebenezer Granger in 1821 (3, 5-7). 

 The anthracite field was first described in 1822 by Zach- 

 ariah Cist (4, 1) and then by Benjamin Silliman (10, 

 331-351, 1826) ; that of western Pennsylvania was 

 described by William Meade in 1828 (13, 32). 



The Lower Carboniferous was first recognized by W. 

 W. Mather in 1838 (34, 356). Later, through the work 

 of Alexander Winchell (1824-1891), beginning in 1862 

 (33, 352) and continuing until 1871, and through the 

 surveys of Iowa (1855-1858), Illinois (essentially the 

 work of A. H. Worthen, 1858-1888), Ohio (1838, Mather, 

 etc.), and Indiana (Owen, etc., 1838), there was even- 

 tually worked out the following succession: 



Permian period. 



Upper Barren series. 

 Dunkard group. 

 Washington group. 

 Pennsylvanian period. 



Upper Productive Coal series. Monongahela series. 

 Lower Barren Coal Measures. Conemaugh series. 

 Lower Productive Coal Measures. Allegheny series. 

 Pottsville series. 



The New York System. We now come to the epochal 

 survey of the State of New York, one that established 

 the principles of, and put order into, American strati- 

 graphy from the Upper Cambrian to the top of the 

 Devonian. No better area could have been selected for 

 the establishing of this sequence. This survey also 

 developed a stratigraphic nomenclature based on New 

 York localities and rock exposures, and made full use of 

 the entombed fossils in correlation. Incidentally it devel- 

 oped and brought into prominence James Hall, who con- 

 tinued the stratigraphic work so well begun and who 

 also laid the foundation for paleontology in America, 

 becoming its leading invertebrate worker. 



This work is reviewed at great length in the Journal 

 in the volumes for 1844-1847 by D. D. Owen. Evidently 

 it followed too new a plan to receive fulsome praise from 

 conservative Owen, as it should have. He remarks that 

 the volumes ' ' are not a little prolix, are voluminous and 





