82 AIR-BREATHERS OP THE COAL PERIOD. 



spend a few days in renewed explorations of the cliffs of the South 

 Joggins. The object specially in view was the thorough examina- 

 tion of the beds of the true coal measures, with reference to their 

 contained fossils, and the conditions of accumulation of the coal ; and 

 the results were given to the world in a joint paper on " The re- 

 mains of a reptile and a land-shell discovered in the interior of an 

 erect tree in the coal measures of -N"ova Scotia," and in the writer's 

 paper on the " Coal Measures of the South Joggins ;'■'* while other 

 important investigations grew out of the following up of these 

 researches, and much matter in relation to the vegetable fossils still 

 remains to be worked up. It is with the more striking fact of 

 the discovery of the remains of a reptile in the coal measures that 

 we have now to do. 



The South Joggins Section is, among other things, remarkable 

 for the number of beds which contain remains of erect trees- 

 imbedded in situ: these trees are for the most part Sigillariae v 

 varying in diameter from six inches to five feet. They have grown 

 in underclays and we; soils, similar to those in which the coal was 

 accumulated ; and these having been submerged or buried by 

 mud carried down by inundations, the trees, killed by the accu- 

 mulations around their stems, have decayed, and their tops being- 

 broken off at the level of the mud or sand, the cylindrical cavi- 

 ties, left open by the disappearance of the wood, and preserved in 

 their form by the greater durability of the bark, have been filled 

 with sand and clay. This, now hardened into stone, constitutes 

 pillar-like casts of the trees, which may often be seen exposed in 

 the clifts, and which, as these waste away, fall upon the beach. 

 The sandstones enveloping these pillared trunks of the ancient 

 Sigillariee of the coal, are laminated or bedded, and the larninse, 

 when exposed, split apart with the weather, so that the trees 

 themselves become split across; this being often aided by the 

 arrangement of the matter within the trunks, in layers more or 

 less corresponding to those without. Thus one of these fossil trees- 

 usually falls to the beach in a series of discs, somewhat resembling 

 the grindstones which are extensively manufactured on the coast, 

 The surfaces of these fragments often exhibit remains of plants 

 which have been washed into the hollow trunks and have been 

 imbedded there ; and in our explorations of the shore, we always 

 carefully scrutinized such specimens, both with the view of observ- 



* Journal of the Geological Society of London; Vols, ix and x ; and 

 Acadian Geology. 



