EXPLANATION OF JOGGINS SECTION. 199 



erect tree were removed or decayed, and the sands next succeeding 

 contain only drift vegetable fragments, having Spirorbis attached to 

 them. Above these is an inch of coal, loaded with Cordaites, and it 

 is to be observed that this is the second instance of thin coals of this 

 kind without Stigniaria underclays. Immediately above this is a 

 sandy soil with Stigmaria and rootlets, but without coal or erect trees. 

 Shales and sandstones succeed ; and above these we have a very thick 

 imderclay full of rootlets. This soil, after the growth upon it of coaly 

 matter, and a forest or successive forests of Sif/illaria, was submerged 

 in such circumstances that scarcely any mechanical detritus was 

 deposited upon it. The trees remained erect in the bottom of clear 

 waters, inhabited by fishes and Cythere, until SjJ/rorhis attached itself to 

 their trunks. They at length fell and sank to the bottom ; and, with 

 the vegetable soil, form a bed of impure coal four inches in thickness, 

 and abounding in scales of fishes and trunks covered with Spiroi^his. 

 Long after the forest disappeared, these aquatic conditions continued, 

 and ten inches of calcareo-bituminous shale with Naiadites, fish-scales, 

 and Cythere were deposited, as usual passing upward into barren gray 

 shale. This is a fine instance of an order of succession which we had 

 frequent occasion to notice in the earlier part of the section. 



In the next Subdivision the waters retain their dominion, though 

 probably diminishing in depth, in consequence of the deposition of 

 detrital matter. The sandstones of this group are very uniform and 

 evenly bedded, as compared with those in the last, and present no 

 indications of vicinity to shores or water-courses, except in the presence 

 of drift-wood, and of singular scratches and furrows on the surfaces of 

 the shales, fine casts of which have been taken by the overlying sand. 

 Scratches and marks of this kind are very frequent in the Coal Forma- 

 tion. They occur on a grand scale in the Pictou freestone quarries, 

 and are also very abundant near Tatamagouche. Many of them might 

 very easily be included in the convenient tribe of Fucoides, that is, 

 remains of sea-weeds, but their want of uniformity in everything 

 except direction, their want of organic matter, and occurrence in beds 

 containing drift-wood, make it most probable that they were scratches 

 produced by the roots and branches of trees borne over the sui'face by 

 currents of water, and similar to those which may be seen on the 

 inundated mud-flats of wooded countries. Such marks are usually 

 straiglit, like diluvial stria;, but when stumps or tree-tops ground and 

 are borne off, the most fantastic markings are produced, j)artly by the 

 eddying of the current around the obstacles opposed to it. 



In Subdivision XXV, we have a dense series of fossil soils, with thin 

 coaly layers. It terminates upwards in bituminous limestone, with its 



