252 THE CARBONIFEROUS SYSTEM. 



that of the corresponding rocks on the north or Cobequid side is 

 very coarse, being made up of large pebbles and even stones of con- 

 siderable size. Similar differences occur in modern seas, and depend 

 on the configuration and elevation of coasts, and their comparative 

 exposure to the sea-swell and prevailing winds. The deposits in the 

 more central part of the district are more uniform and persistent in 

 their character. 



In noticing this Carboniferous area, I shall describe, in the first 

 place, some of the localities and sections in which the arrangement 

 and character of its rocks are most distinctly exposed ; and these will 

 afford us opportunities of studying the Lower Carboniferous series, 

 almost as perfect as those which we enjoyed at the Joggins in the 

 case of the Coal formation deposits. 



At Wolfville and Lower Horton, in the south-western part of the 

 district, we find the Lower Carboniferous beds to consist of gray sand- 

 stones and dark shales, resting on the edges of the slates of the Gas- 

 pereau River. In the road-cuttings in Lower Horton, the sandstones 

 may be seen to contain fine specimens of Lepidodendron, a genus of 

 which we have already seen examples at the Joggins. There appear 

 to be two or three species of this genus in the beds of Horton Bluff, 

 and one of them at least is distinct from any of those found in the true 

 Coal measures, and is most characteristic of this Lower Coal formation. 

 It is the species which I have named L. corrugatum (Fig. 74), and is 

 found on the same geological horizon as far west as Ohio. It is also 

 closely allied to a characteristic species of this age in England and 

 on the continent of Europe. With these Lepidodendra are found 

 at Horton Bluff several other fossil plants, more especially the fine 

 fem (Fig. 75), which I have named Cyclopteris Acadica, Cordaites 

 (Fig. 76), Stigmaria, and the conifer Dadoxylon antiquius. 



The Cyclopteris Acadica was a magnificent fern, unsurpassed by 

 any in the Middle Coal formation. Its leaf-stalks are often two 

 inches in diameter, and the frond, with its hundreds of wedge-shaped 

 leaflets, must have been several feet in breadth. In some of the shales 

 at the same locality fish-scales are extremely abundant, and make up 

 apparently the greater part of the mass of some thin beds. The whole 

 of these rocks are, however, much better seen at Horton Bluff, a fine 

 range of cliffs extending along the west side of the Avon estuary. 

 At this place the beds do not dip regularly in the same direction, but 

 have been broken into great masses which dip in different ways, and 

 have been fractured and displaced by faults or slips of one mass or 

 another up or down, so as to break the continuity of the layers. Such 

 disturbances are very frequent in all the sections of this district, and 



