152 Geological Society. 



them obliquely. They always increase in number in the proximity 

 of a seam of coal. In one part, however, of the Chignecto coast, 

 called South Joggins, where the nineteen seams of coal already 

 mentioned occur for the space of three-quarters of a mile, and in a 

 thickness of strata amounting to 1800 feet, the fossil trees which 

 occur are all perpendicular to the strata. In tracing these seams of 

 coal along the ravines to the distance of six miles from the coast, 

 trees have been observed in the same vertical position in respect of 

 the strata. The cliffs at this spot are from 80 to 100 feet in height, 

 and consist of grey and reddish sandstone, bituminous blue shale, 

 shelly limestone, clay ironstone and coal. The strata are rapidly 

 degraded, so that at every successive visit which the author has 

 made to the spot during the last ten years, he found that trees which 

 he had originally observed had disappeared, and that others were 

 exposed in their stead. At the last visit he made, which was in 

 July last, in company with Mr. Lyell, seventeen trees were exposed 

 to view, and this number was rather less than he had seen on former 

 occasions. The ordinary length of these trunks is from 10 to 30 

 feet, but some have been observed that were 50 or even 70 feet 

 long. They vary in diameter from 6 inches to 3 feet ; but one 

 was 4 feet 6 inches across. Most frequently their lower extremities 

 are situated in shale ; but sometimes they spring from the coal 

 itself, and when that is the case, they never pass through the seam 

 of coal. Sometimes their roots branch out into the shale or sand- 

 stone they rest upon. 



At the place above referred to, ten miles north of Truro, the 

 strata above and below the coal abound in trunks, bi'anches, and 

 leaves of large fossil trees. The exterior of the trunks is coal ; and 

 the interior is usually sandstone and fine clay. In one tree the 

 whole trunk was coal, except a flattened portion resembling the pith 

 and extending through the centre of the tree from one extremity to 

 the other. At the spot on the Moose River, where the coal-mea- 

 sures rest on old red sandstone, a fossil tree 30 inches in diameter is 

 seen in black shale and dark-coloured sandstone. 



Besides the coal district already described there is an area near 

 Falmouth and Windsor of seventy square miles, in which though 

 the coal has not been discovered, yet the ferns, Sligmaria, and other 

 fossil plants which the sandstones and shales of that area contain, 

 sufficiently establish the point that it belongs to the coal-measures. 



6, New red sandstone. —At the Jolly and Debert Rivers the coal- 

 measures are overlaid by a red sandstone, associated with gj^psum 

 and limestone. In the districts of Windsor, Rawdon, and Douglas, 

 to the south of the Basin of Mines, and in that of Truro on the east 

 of that basin, a bright red micaceous sandstone prevails, alternating 

 with strata of red shale and indurated clay, and containing calca- 

 reous, gypseous, and red argillaceous marls. It is characterised by 

 containing thick beds of compact gypsum and limestone, and by its 

 being the seat of salt springs. The author regards it as agreeing 

 in geological position with the sandstone above-mentioned. 



7. Intrusive Igneous Rocks, — The whole north-west coast of the 



