22 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Nov. 2, 



attained the depth of 9 feet, at which depth the original large Siffillarice, 

 that had grown immediately over the coal, were broken off, and their 

 hollow trunks filled with sand. Before being filled with sand, these 

 trees, while hollow, must for some time have projected from a swamp or 

 terrestrial surface, such as that which immediately succeeds them in 

 ascending order ; and it is no doubt to this circumstance that we owe the 

 occurrence, in one of them, of reptilian remains and land- shells, as well 

 as a mass of vegetable fragments, such as Calmnites, Poacites, and a 

 Lepidostrohus *, evidently introduced before the sedimentary matter, 

 and forming just such a mass as might be supposed likely to fall into 

 an open hole in a forest or swamp. (5.) The remaining beds of this 

 group evidence the continuation of swamp- conditions for a long time 

 after the trees last noticed were completely buried. They include, in 

 a thickness of 28 feet, three underclays supporting coaly beds, and 

 one with erect stumps ; one of them with Stigmarian roots and 

 ribbed. One of the coaly beds, which alternates with laminae of 

 shale, is filled with flattened trunks of Sigillaria and Lepidodeiidron, 

 which probably grew on the surfaces on which they now lie, and 

 indicate how small a thickness of coaly matter may mark the time 

 required for the growth and decay of many successive forests. 



On the whole, we can scarcely err in affirming that the habitat of 

 the Bendi^erpeton Acadianum and its associates was a peaty and 

 muddy swamp, occasionally or periodically inundated, and in which 

 growing trees and Calamite brakes were being gradually buried in 

 sediment, while others were taking root at higher levels, just as now 

 happens in the alluvial flats of large rivers. 



I may add that in 1853 I fomid, in some additional fragments of 

 the reptiliferous tree collected by Mr. Boggs, superintendent of the 

 Joggins mine, a second, though imperfect specimen of the land- 

 shell figured m the paper already referred to (vol. ix. pi. 4), and a 

 few fragments of bone, apparently vertebrse. 



Group XVI. consists of one thick bed of grey sandstone, with 

 prostrate carbonized trunks. The sandstone is highly siliceous, and 

 of the kind used for grindstones. It is the result of the complete 

 submergence of the swamps of the last group, and their invasion by 

 sand-bearing currents. 



The next Group commences with the growth of Calmnites on the 

 surface of the great sand bed last noticed, after which there was the 

 formation of an underclay and coal, the latter being afterwards inun- 

 dated, and the plants at its surface overgrown with Sjnrorbis. In 

 the shale covering this coal, about 14 feet above its surface, is a bed 

 with shrinkage cracks, and containing a stool of Stigmaria, one of 

 the roots of which was traced 9^ feet. Its rootlets were attached, 

 so that it can scarcely have been a drift-stump ; and if now in situ, 

 it must have grown on a mud-bank alternately inundated and dry, 

 like the present salt-marshes of the Bay of Fimdy. The Stiginaria 

 in this bed is not of the most common variety or species. It has 

 round marks regularly arranged, but flat, and without depressed 

 areolae, as represented in fig. 13, ms. That growth on occasionally 

 * Found in 1853. 



