IN THK RED SANDSTONE OF I'OTTSVILLE. 5 



ing with its place in the scries of European rocks; and Mr. T. always considered For. 

 No. 11 as the '■'■upper series of tlic old red sandsloiic.^^ In his paper on the " Carboniferous 

 Series of the United States^' (Mag. of Nat. Hist., vol. 9, 1836,) he makes the Ok! Red 

 Sandstone which underlies the coal formation of Pennsylvania, equivalent to that in 

 Europe. He does not agree with Mr. Weaver in his views regarding this red sandstone. 

 Mr. Taylor arranges these rocks thus : — 



1. The (almost) horizontal carboniferous series. This includes the conglomerate on 

 which the series is unquestionably based. 



2. " The Old Red Sandstone and Red shales, many thousand feet thick," — nearly verti- 

 cal, in central Pennsylvania — pass immediately beneath the bituminous coal field of Penn- 

 sylvania, in Tioga county. 



3. The upper transition and grauwacke series commences at the termination of the red 

 shales and sandstones. 



He states that the "diagrams which have been laboriously worked out, exhibit no lime- 

 stone in Pennsylvania between the secondary coal series and his Old Red Sandstone group, 

 which average a mile thick." And again he says, "I see that both in the acknowledged 

 secondary bituminous coal region, and in those of the anthracite districts, the car- 

 bonaceous deposits are alike based on red sandstones and red shales." — Always consider- 

 ing these red sandstones as equivalent to the Old Red Sandstone of Europe. 



In the New York reports, Mr. Hall considers "No. 11 of the Pennsylvania Survey" as 

 equivalent to the "Old Red Sandstone," both of which he refers to the "Catskill group." 

 (Part IV., Geology, p. 278.) In the diagram on the same page, he represents the Old Red 

 Sandstone as immediately underlying the conglomerate which again underlies the " coal 

 measures of Pennsylvania." In his annual report, 1840, p. 394, he says that "this rock 

 (Old Red Sandstone) forms the limit between the Silurian and Carboniferous system, and 

 may be regarded as one of the most important of the whole series;" and he gives Mr. 

 Taylor the credit of pointing out the existence of this rock and its analogy to the Old 

 Red Sandstone of Europe. In his geology, part 4, p. 516, he enforces this opinion by say- 

 ing, "there remains no doubt but the sedimentary rocks of New York correspond with 

 those of the Silurian and old red systems, as described in the Silurian Researches. If the 

 Devonian is to be regarded as a distinct system, we shall find its representative in the 

 Chemung and Portage groups, with, perhaps, a part of the Hamilton group." Mr. Conrad 

 too, recognises the old red system in his table of Formations, and places the " Old Red 

 Sandstone," of Blossburg, Penna., immediately above the Ludlow rocks of the Silurian sys- 

 tem. (American Journal vol. 38, p. 89.) And in his report of 1841, when mentioning 

 the Devonian group, he says, that " great tracts of this system lie between Carbondale 

 in Pennsylvania, and the upper Silurian district of New York, nearly all of which is quite 

 destitute of organic remains, except those of vegetables, (p. 42.) Dr. Emmons and Mr. 

 Vanu.xem seem, in their reports, to recognise the Catskill group as being analogous to 

 the Old Red Sandstone of Europe, and that it immediately underlays the great coal forma- 

 tion of Pennsylvania. These inosculating strata have always presented difficulties to 

 the geologist, and Mr. Vanuxem, when mentioning the differences of opinion, as to the 



