128 THE DEVONIAN AND CARBONIFEROUS. |bull.80. 



ments. With this as a working hypothesis the paper on u Recurrence 

 of faunas n was the announcement of the first confirmatory evidence 

 actually seen. BarrandVs theory of " Colonies * considered the laws con- 

 cerned as exceptional ; the theory of the recurrence of faunas was set 

 forth as the formulation of a general law. 



Investigations in the same line were extended by the author west- 

 ward from the meridian of Cayuga Lake, New York State, across the 

 State, northwestern Pennsylvania, and the eastern part of Ohio. The 

 rocks studied were of Devonian and Lower Carboniferous, age, and the 

 problems were the same over which the Pennsylvania geologists were 

 struggling. 



In 1883, Mr. Claypole 1 reported that the Catskill group of, New York 

 had hitherto been considered as non-fossiliferous, and as separating the 

 characteristic Devonian and Carboniferous faunas. Further examina- 

 tion, however, proved that these rocks contained a scattered fauna 

 consisting offish and plant remains. From a study of these deposits 

 in central Pennsylvania, the author reached the following conclusions: 



(1) That the lower portion of the Ponent Red sandstone and shale (Catskill) is 

 less barren of organic remains than has been supposed. (2) That HoloptychUis and 

 Bothriolepis are not exclusively Catskill fauna, and (3) That the Ponent group 

 differs from what it is generally understood to be, the contained fossils indicating 

 that there are Chemung and also Carboniferous faunas included in rocks called 

 Ponent. 3 



Mr. Claypole, 3 during the same year, communicated several other 

 papers bearing more or less upon the general discussion. 



In the same year (1883) in which Report G 7 of the second geological 

 survey of Pennsylvania appeared, the manuscript of Bulletin 3 of the 

 U. S. Geological Survey 4 was furnished, though not published till the 

 following year. 



The bulletin is a report upon the constitution, the order, and relative 

 position of the fossil faunas in a continuous section of the rocks, from 

 the Genesee shales through the Upper Devonian to the first appearance 

 of a coal bed at the Barclay coal mines in southern Bradford County, 

 Pennsylvania. 



1 Claypole, E. W. : On the occurence of fossiliferous strata in the Lower Ponent (Catskill) group of 

 middle Pennsylvania. Am. Nat., vol. 17, 1883, pp. 274-282. 



2 Ibid.,p.282. 



3 Claypole, E. W. : Note on the occurrence of Holoptychius about 500 feet below the recognized top 

 of the Chemung group, in Bradford County. Proc. Am. Phil. Soc, vol. 20, 1883, p. 531. 



On a mass of Catskill rocks, supposed to exist on the not th bank of Towanda Creek, near Franklin. 

 Proc. Am. Phil. Soc, vol. 20, 1883, pp. 531-533, 535. 



On two small patches of Catskill, represented near Leroy, on the map in report G, of the second geol. 

 survey of Pennsylvania. Proc. Am. Phil. Soc, voL 20, 1883, pp 533-534. 



On the Kingsmill white sandstone. Am. Phil. Soc, Proc, vol. 20, 1883, pp. 666-677. 



On the equivalent of the New York Portage, in Perry County, middle Pennsylvania. Am. Phil. Soc- 

 Proc, vol. 21, 1883, pp. 250-255. 



On a large crustacean from the Catskill group of Pennsylvania. Am. Ass. Proc, vol. 32, 1883, p. 265. 



4 On the fossil faunas of the Upper Devonian along the meridian of 76° 30', from Tompkins County, 

 New York, to Bradford County, Pennsylvania, by Henry S. Williams. 



A notice of the general results, embodied in the bulletin, appeared in Science, December 28, 1883. 

 (Comparative Paleontology of the Devonian formations, Science, vol. 2, p. 836.) 



