1883.] 673 [Lesley. 



that the Panama conglomerate belongs to the base of the Catskill, and 

 probably also the Marshall grits of Michigan. 



No representative of the Catskill has yet been found or recognized so far 

 as I am aware in Michigan. A gap is left in the Michigan section between 

 the Chemung and the Lower Carboniferous. 



Mr. Lesley remarked on this paper of Prof. Claypole's, 

 that he could not agree with the sentiment expressed in its 

 introduction respecting the doubtful propriety of the use of 

 the term " Catskill formation " as an equivalent of Prof. 

 Roger's " Ponent formation." 



It is a mistake to suppose that the " Catskill formation " was based in 

 any degree upon fossil forms, any more than was the "Ponent." The 

 two terms are completely and exactly identical. The New York geologist 

 meant by it the red rocks constituting the Catskill Mountain massif, 

 overlooking the Hudson valley, and extending unbroken far into Penn- 

 sylvania, and in fact through Pennsylvania into Maryland and Virginia. 

 It was described as a pile of nearly horizontal Devonian strata destitute 

 of fossils remains, except a few macerated plants and one or two types of 

 fish. Mr. Rogers had to describe the same mass of strata, with the same 

 lithological constitution and topographical aspect, and perfectly continuous 

 with it geographically. There never was any question, nor is there now 

 any question of the identity of this mass of strata in the two States. But 

 as Mr. Rogers declined to accept any of the Palaeozoic names of New York 

 and invented a new nomenclature for his own use in Pennsylvania, he sub- 

 stituted Ponent for " Catskill," as he substituted Medidial for " Oriskany," 

 Postmedidal for "Upper Heldcrberg," Cadent {or "Hamilton," Vergent 

 for "Chemung and Portage," &c. The only essential change he made 

 was in giving a separate name. Vespertine, to the gray sandstone strata 

 forming the peaks of the Catskill. These had been left unnamed (or in- 

 cluded under the general name "Catskill") because the N. Y. geologists 

 had no clue to their topographical significance, which only appears after 

 passing west of the Lehigh, where, upturned vertically, they constitute a 

 separate range of mountain. 



In the reports of the Second Geological Survey the transcendental 

 nomenclature of the brothers Rogers has been set aside in favor of the 

 older, classical and generally accepted nomenclature of the New York 

 geologists. As the gray sands of the Catskill peaks form the top coating of 

 the Pocono tableland in Pennsylvania, the name "Pocono" has been 

 substituted for Vespertine ; but this leaves the term Ponent represented, as 

 it always has been, by " Catskill." 



