﻿Geology and Natural History. 407 



A third point considered was the termination of the adjective 

 terms used to indicate subdivisions under the above heads. M. 

 Lapparent thought that it was not best to make any definite 

 proposal at present, on the ground that terms in use were well 

 understood, and the probability of having to modify again. But 

 M. Renevier proposed the following scheme, which was adopted : 

 that the adjective terms of a Group, should have the termination 

 ary (aire in French) as Primary, etc, ; of a System, ic (ique, Fr.) ; 

 of a Stage, ian (ten, Fr.) ; of a Sub-stage, ine (in, Fr.). 



The following points referred to the committee were answered 

 as follows : 



The divisions of highest rank should be based on paleontological 

 characters of universal or world-wide application. The Systems 

 should be marked off by comprehensive facts in paleontology 

 indicative of the general march of progress, especially facts that 

 relate to pelagic species. The common characters of the Systems 

 will necessarily serve for the defining of the Sub-groups. The 

 Stages should be characterized by distinct pelagic faunas ; and 

 the Sub-stages should have a regional value. Inferior divisions, 

 having only a local value, were regarded as not coming under the 

 consideration of the International Congress. The committee also 

 decided that a stratigraphic argument needed always to be con- 

 firmed by paleontological evidence. j. d. d. 



2. Geological Age of the North Atlantic Oceanic basin and 

 Origin of Eastern American sediments. — In Nature, of Sept. 23, 

 Professor Edward Hull, of Dublin, objects to a statement in 

 President Dawson's Address in which the latter says : " I prefer, 

 with Hall, to consider these belts of sediments as, in the main, the 

 deposits of northern currents, and derived from Arctic land, and 

 that, like the great banks of the American coast o( the present 

 day, which are being built up by the present Arctic currents, they 

 had little to do with any direct drainage from the adjacent 

 shore," Professor Hull observing rightly that the deposits 

 spread widely over the continent without reference to the shore 

 line, and that the currents are inadequate in other respects. Mr. 

 Hull states the view he has held, not that the Arctic lands were 

 the source, but the region of the Atlantic, "towards which the 

 sediments thicken, and opposite to that in which the limestones 

 are most developed ;" and thence, that the conclusion is inevitable 

 " that the Atlantic w T as in the main a land-surface in Paleozoic 

 times." 



Professor Hull misunderstands American geology in an impor- 

 tant respect. The Upper Silurian and Devoniau deposits, which 

 have so great thickness to the eastward, stretch northward over 

 central and southern New York, to a large extent behind or west 

 of the Green Mountain region, which was already in shallow 

 water, and probably emerged land ; and the Carboniferous forma- 

 tion extends up in the same direction, though to a less distance. 

 Further, the Appalachian Paleozoic beds from their beginning 

 were laid down to a very great extent to the west of the Archsea 



