STRATIGRAPHIC AND GEOGRAPHIC DISTRIBUTION. 



21 



in point of fact, we know onl}^ one set of beds at the South Joggins in which such remains 

 so preserved occur ; nor is there, so far as I am aware, any other known instance elsewhere. 

 Even in the beds in question, only a portion of the trees, about 15 out of 30, have afforded 

 animal remains. We have, however, thus been enabled to obtain specimens of a number of 

 species which would probably otherwise have been unknown, being less likely than others to 

 be preserved in properly aqueous deposits. Such discoveries on the one hand impress us with 

 the imperfection of the geological record ; on the other, they show us the singular provisions 

 which have been made in the course of geological time for preserving the relics of the 

 ancient world, and which await the industry and skill of collectors to disclose their hidden 

 treasures. 



"There is evidence in coprolitic matter on one of the surfaces within the trunks, and 

 also in certain trails on these surfaces, that some of the imprisoned animals lived for a time 

 in their subterranean prisons; that they crept around their walls in search of a way of 

 escape, and that the larger animals fed on smaller species entrapped along with them." 



After the discovery of these en- 

 tombed amphibians Sir William Dawson 

 was given a grant of £50 from the Gov- 

 ernment Fund by the council of the Royal 

 Society of London, to aid in the extrac- 

 tion of these trees and the collection of 

 their contents. The trees were carefully 

 taken out and their contents examined ; 

 the portions containing the animal re- 

 mains were carefully boxed to be taken 

 to Montreal for final cleaning and study. 

 Erosion goes on rapidly at the South 

 Joggins, but no one has paid any atten- 

 tion to the occurrence of Amphibia along 

 the coast of Nova Scotia within recent 

 years. 



iq) A deposit which will be of un- 

 doubted interest in connection with the 

 occurrence of Amphibia in the Coal 

 Measures is that which outcrops along 

 the banks of Rock Creek in the south- 

 western part of Douglas County, Kansas, 



^ 



^^^^ 





-«^fc. 





i:^ 



Fig. 5. — Dawson's tree No. 13 at the South Joggins, Nova Scotia. 

 Upper part, in situ, in the reef after it had been exposed by 

 blasting. (After Dawson, based on a photograph.) 



in Marion Township (Township 14 south, Range 18 east, SW. and SE. quarters of 

 section 7), about 2 miles from the now-abandoned post-oflfice of Twin Mounds, so 

 called from the two flat-topped, elongated mounds of Oread limestone to the west 

 of the town. 



The interest in these beds is not due to the discovery of Amphibia in them, but 

 the possibilities of such discoveries. This is indicated by the occurrence of fossils, 

 in nodules similar to those obtained from Mazon Creek, which are identical gener- 

 ically, and in most cases specifically, with the Mazon Creek animals and plants. 



