NORTH SYDNEY AND SYDNEY MINES, C. B. — DeWOLFE. 311 



while all except one have shale or marl immediately overlying. 

 In the exceptional case, sandstone is above limestone. 



Fossils. — The strata next below the Main seam give the 

 best illustrations of erect tree trunks, of any on this coast. 

 There Sigillaria from one to three feet in diameter show eight 

 to ten feet of their length through beds of sand and shale. I 

 found none with roots attached, but in one case the trunk is 

 easily traced into the shale overlying a seam. The trees visible 

 in these beds taper i-apidly. The original bark forms a thin 

 layer of glossy coal, the interior being filled with shale or fine 

 sandstone. 



Fern-like leaves and petioles are abundant in the sandstone 

 surrounding the erect trees, lying with so little distortion that 

 they must have fallen into still water or soft mud, and have 

 been buried before they became disarranged. In several cases, 

 leaves appear in the inferior layers, but no branches ; and in 

 higher strata branches are found. The rising sediment may 

 have killed the tree graduall}^ leaving it at last shorn of its 

 leaves, but with branches intact. These fell later into sediment 

 newer than that which had received the leaves. The time came, 

 however, when the dead top fell also, and was borne awtxy ; for 

 now the truncated bole stands with overlying masses of rock 

 which contain no trace of the missing wood. 



While the sediment must have accumulated comparatively 

 rapidly, to bury trees before they could decay and fall, it did 

 not prevent other trees from taking root and growing tj a 

 considerable size. For erect trees are found in the same cliff at 

 but slightly different levels. They were probably swift growers, 

 but perhaps teuaceous of life and slow to decay. These quali- 

 ties would readily explain the conditions under which we now 

 find them. That the bark decaj-ed more slowly than the wood 

 is evident from finding the former carbonized, while the space 

 once occupied by the latter is now filled with sandstone, or less 

 commonl}^ clay or shale. 



