156 THE DEVONIAN AND CARBONIFEROUS. [bull. 80. 



former terra to the limestone which Prof. Hall called " Carboniferous 

 limestone." 



Mr. Lyon's classification was as follows: l 



Feet. 

 a. Coal Measures 1,200 



I. Fifth sandstone 40-100") 



c. Fourth limestone 10-40 



d. Beds of colored clays 0-84 



e. Fourth sandstone 0- (5 



/. Third limestone 25- 50 



g. Aluminous shale 0- 53 } Millstone grit series. 



h. Third sandstone 25- 40 



i. Second limestone 25-50 



k. Second sandstone 75-90 



I. First limestone 15-20 



m. First sandstone 10- 30 , 



n. Cavernous limestone 200-400^ 



o. Middle limestone 500-600 | 



p. Sandstones and shales 205-300 | 



q. Black slate 50-100 | 



r. Encrinital limestone 0- 8| 



8. Hydraulic limestone 0-20 } Subcarboniferous series. 



t. Spirifer bed .' 0- 3| 



u. Nucleocriuus bed.. 0- 2| 



v. Turbobed 6- 10 



w. Coral bed 5- 10 | 



x. Catenipora beds ,. 15- 40 J 



The divisions p, o, n, constituted what he called u Subcarboniferous 

 limestone," the synonyms for which were " Barren limestone," " Cav- 

 ernous limestone," "Carboniferous limestone," and "Mountain lime- 

 stone" of the Europeans. 



Division o was the middle member of the Subcarboniferous limestone, 

 and 180 feet above its base is a bed' which was regarded as equivalent 

 to Hall's " Spurgen Hill beds," of Washington County, Indiana, which 

 Prof. Hall considered as equivalent to the " Warsaw limestone." 



The lower member of the " Subcarboniferous limestone " (p) " is fre- 

 quently distinguished as the Knobstone beds." 3 The " Black slate" with 

 Lingulas (q) the author put in the " Devonian," and he stated that di- 

 vision p has been also placed in the Devonian, but that the paleonto- 

 logic evidence of the Goniatite beds at Rockford, Indiana, would point 

 to its inclusion with the Subcarboniferous limestones, instead of in the 

 Devonian. 4 



The beds r, s, t, u, v, w, x, " thin out rapidly and disappear entirely 

 about twenty miles south of Louisville." 4 



This classification was in accord with the general usage of Dr. Owen 

 and those who had assisted him in his surveys in the Mississippi Valley. 



James Hall, in the various papers in which he attempted to correlate 

 the Western deposits with his New York system, used the name "Car- 

 boniferous limestone " for the calcareous portion of the " Subcarbonifer- 

 ous series" of Owen, and applied " Subcarboniferous" to his so-called 

 "Chemung group," which in New York is of Devonian age. The West- 

 ern geologists clearly understood the relation of the so-called "Che- 

 mung" of the Mississippi Valley to these "Carboniferous limestones," 



1 Discussion of the Strategraphical Arrangement of the Rocks of Kentucky. Trans. St. Louis Acad. 

 Sci., vol.1, I860, p. 641. 



2 Ibid., p. 617. «Ibid.,619. «Ib.,p.620. 



