176 SUBDIVISIONS OF THE CARBONIFEROUS SYSTEM 
Just where to place this Windsor formation in the column 
of Palseozoic formations has not yet been detinitely ascertained. 
Whether it is to be classed as one of the EKo-Carboniferous sedi- 
ments, or whether it constitutes a factor or part of what may be 
termed, according to Prof. H. S. Williams’s very appropriate 
classfication, Meso-Carboniferous, is the question occupying our 
mind at present. It is, nevertheless, to be remarked that the 
fauna it contains is one in which so far not one of the Upper- 
most Devonian fossils of the Gaspé and other regions of Eastern 
Canada have been detected. 
The occurrence of this formation in certain basins of Nova 
Scotia marks a cessation of the conditions existing in the areas 
which these limestones cover, showing that the sea or Atlantic 
waters in Carboniferous times extended over the Eo-carboniferous 
deposits previously laid down, which had been subjected to 
subsidence and erosion previous to their being overlaid, whilst 
the vegetation and climate did not, probably, change very 
materially in the high land during this period of submergence 
and encroachment of the sea. A period of elevation evidently 
must have followed the deposition of the limestones, marls, &c., 
and sandstones and mudstones and shales were deposited, to be 
followed later again by sandstones with shales and coal seams 
peculiar to the “Coal Measures ” and “ Millstone Grit ” formations. 
Such deposits are essentially terrigenous as to their origin 
and the structure, as well as origin and mode of deposition of 
the Coal Measures need not be described. The flora and fauna 
they hold mark the estuarine conditions existing and prevailing 
at the time, also the luxuriant growth of plants on land with 
the contemporaneous animal life of the period both in the water 
and on the land also. 
A brief summary of the succession of the sediments in the 
Carboniferous of Nova Scotia in Pictou, Colchester and Cumber- 
land counties in part, such as the writer has observed it in 
numerous outcrops and localities, gives the following section in 
ascending order :— 
1. Riversdale and Union formations: Consisting of red 
