172 



tracings of the Virginia and Pennsylvania Reports, and they have 

 since always assigned them a prominent place when treating of 

 the order and character of our paleozoic rocks. The carbonife- 

 rous relations of the lower or Vespertine group, taken in connec- 

 tion with its depth beneath the true coal measures, were early 

 recognized as a feature of peculiar geological interest, and in 

 1849 Prof. Rogers had made it the subject of a special communi- 

 cation to the British Association, on which occasion he called the 

 attention of British geologists to the existence in the United 

 States of this group of plant-bearing strata, and even of coal 

 measures, beneath several thousand feet of marine deposits, having 

 the general characters of the great carboniferous limestone of Eu- 

 rope, and remarked upon the vast interval of formative actions 

 which must have intervened between the production of these ear- 

 liest carboniferous rocks and the true coal series. This slight 

 reference to the history of the subject will show how early and by 

 whom the two formations in question were first clearly recognized 

 and introduced into a classification of the North American strata. 



In the recent publications of Prof. Dawson on the carboniferous 

 rocks of New Brunswick and Nova Scotia, so ably explored by 

 himself, Sir Wm. Logan, and Prof. Robb, w-e find this geologist 

 virtually recognizing a similar binary subdivision of the great 

 series of deposits which form the lower carboniferous system of 

 these regions, describing those which lie at the base of the series 

 as the lower coal measures, or lower freshwater or estuarine de- 

 posits, and the remainder as the lower carboniferous marine 

 deposits. 



Combining the data collected by Prof. Dawson and others with 

 his own observations during the past season. Prof. Rogers had be- 

 come satisfied of the close parallelism of these two divisions of the 

 carboniferous rocks of Nova Scotia and New Brunswick with the 

 above described Vespertine and Umbral groups respectively, 

 especially as the latter are developed in the valley of the New 

 River, and the adjoining region toward the south. The sand- 

 stones and slates of the Gaspereau, and of Horton Bluffs and 

 Half-way River, as well as other localities on the Bay of Mines, 

 and the corresponding formation containing the asphaltic coal of 

 New Brunswick, all underlying the gypsiferous marls and lime- 

 stone, with carboniferous fossils of these regions, seem to be clearly 



