1862.] 2Q5 [Lesley, 



becomes an additional argument for the identification. For we see 

 in this No. 6 the reproduction, at this immense distance, of the 

 Lower or False Coal-measures of Virginia, where a productive coal 

 system underlies the chocolate shales of Formation No. XI, and not 

 only reappears, with workable beds, in Eastern Kentucky and Middle 

 Tennessee, but projects itself, in a recognizable shape, through West- 

 ern Indiana nearly to Chicago, and through Middle Pennsylvania 

 nearly to the Delaware Iliver. In fact, Lesquereux pronounces the 

 whole coal of Arkansas to belong to this lower system. It may, 

 therefore, very well be found in force in Nova Scotia. Throughout 

 Division No. 6 no bed of respectable size is mentioned. It is an 

 early and imperfect system. 



The chief objections to this hypothesis above sustained, will come, 

 1, from the absence of any general representative for the Millstone 

 Grit or Great Fiasal Conglomerate of the True Coal-measures; 2, 

 from the sub-position of Divisions 7 and 8, 2308 feet of sands, peb- 

 ble-rocks, and limestones; and 3, from the presence at a still lower 

 depth of what seems to be the genuine, massive, subcarboniferous 

 limestone. To break the full force of these objections, I can only 

 remark, 1, that the Pictou coal-basin has a massive Conglomerate 

 under its productive coal-measures, while elsewhere no one Formation 

 of the whole Palaeozoic System is so variable and unreliable and un- 

 identifiable as Formation XII, the Great Conglomerate, technically 

 so called ; 2, that Nos. 7 and 8 may be identified with Formation 

 X; and 3, that the subcarboniferous or Archimedes Limestones of 

 the Western United States not only have been subdivided into five 

 separate formations in the Valley of the Mississippi, but wholly thin 

 away and disappear before crossing the Schuylkill and Lehigh Ilivers 

 on their way to Nova Scotia. Therefore, although the False or 

 Lower Coal-measures of Virginia and Southwestern Pennsylvania are 

 overhtid by limestones with subcarboniferous fossils, the connection, 

 as to llmeatone, is entirely cut away between them and the Nova 

 Scotia deposits, so that the massive gypseous limestones of Nova 

 Scotia may be at any assignable lower level. This argument is ren- 

 dered all the more forcible by the fact that gypsum is unknown in 

 the United States, except in one or two anomalous positions, appa- 

 rently connected with the Lower Silurian Limestones, and in the 

 closed basin of Michigan. 



Beneath the red shale Formation No. XI, we have, in the south- 

 eastern ranges of the Appalachians, nearly three miles' thickness of 

 sedimentary deposits, separable everywhere into three great Forma- 



