238 THE DEVONIAN AND CARBONIFEROUS. [bull. SO. 



relations of Nova Scotia formations are recorded, reviewing the paper 

 above mentioned : 



fThe first section described is situated 14 miles southwest of Fayette- 

 ville, in Washington County, Arkansas, and the second was made from 

 the base to the top of the Boston Mountain, in Johnson County. The 

 Millstone Grit Measures seem more persistent and greater in thickness 

 in Arkansas than in the East, and may be greater than has been made 

 out at Horsehead Mountain. From an examination of these sections, 

 the author thinks that the " Nova Scotia basin is a separate member 

 of our great American coal field," and agrees with Dawson that the 

 flora of both countries is apparently the same. But while Dawson 

 finds abundance of coniferous trees, and English geologists find them 

 abundant in the Coal Measures of England, the author claims, in com- 

 paring sections of the East and West, that he finds none in his western 

 section. The increased thickness of the sandstones and shales of the 

 eastern deposits, in comparison with those of the West, and the local 

 variations, the author accounts for by the fact that they are shore forma- 

 tions, and hence Dawson's sixth objection is not applicable to western 

 deposits. The author in conclusion shows from Dawson's own state- 

 ments that there is a gradual change throughout the flora of the Coal 

 Measures, and even from Devonian to typical Carboniferous plants, 

 while Dawson would claim there was a much less intimate connection 

 between Upper Devonian and Lower Carboniferous than is apparent 

 throughout the whole Carboniferous system. 



G. F. Matthew 1 in 1865 commented on the " Fern ledges " of Lancas- 

 ter, Ne*v Brunswick, in the following way : 



The Middle and Upper Devonian rocks are known under three groups : 

 The " Bloomsbury group," No. 4 of Dawson's list y " Little Eiver group," 

 Nos. 2 and 3, Dawson's list; "Mispeck group," No. 1, Dawson's list. 

 These groups, lying unconformably on the Silurian, and in some places 

 upon the Lauren tian rocks, occupy a great part of the district towards 

 the head of the Bay of Fundy. They contain numerous plant beds, 

 and seem to be connected with those of Perry, Me. St. John County 

 is largely covered by Devonian rocks, and detached pieces occur through- 

 out Charlotte County. Dawson says that "the plant remains combine 

 the features of the Hamilton and Portage groups." Professor Hitch- 

 cock also reports Devonian areas in northern Maine. The thickness of 

 the Devonian sediments below the plant beds is about 5 ; 000 feet. 



The Lower Carboniferous rocks extend over Kings, Albert, and 

 Westmoreland Counties, being about 100 miles in length, with varying 

 width. They also occur along the Keunebeccasis Bay and in detached 

 areas along the Bay of Fundy. They consist mainly of limestones, 

 shales, and sandstones, associated with pyroschists resembling those 



1 Matthew, George F. : On the Devonian plant locality of the "Fern ledges," Lancaster, New Bruns- 

 wick, with a detailed section and notes on the fossils. 



Observations on the Geology of southern New Brunswick, by L. W. Bailey fet al.], pp. 131-140. Fred- 

 ericton, 1805. 



