20 THE COAL MEASURES AMPHIBIA OF NORTH AMERICA. 



(p) All the remains representing the above species were collected by Sir J. Wil- 

 liam Dawson at the South Joggins and at the mines of Albion, with the exception 

 of Eosaurus, which was collected by O. C. Marsh. The collections of Dawson are 

 now in the Peter Redpath Museum of McGill University in Montreal and in the 

 British Museum of Natural History at South Kensington, London. The history of 

 the discovery of the deposits and their amphibian fossils at the South Joggins is so 

 interesting that it was thought worth while to reproduce in large part Dawson's 

 paper "On the Mode of Occurrence of Remains of Land Animals in Erect Trees at 

 the South Joggins, Nova Scotia," published in 1891 in the Transactions of the Royal 

 Society of Canada, section iv, p. 127: 



"The remarkable section of coal-formation rocks at the South Joggins, in Cumberland 

 County, has long been known as one of the most instructive in the world ; exhibiting as it 

 does a thickness of 5,000 feet of strata of coal-formation in a cliff of considerable height, 

 kept clean by the tides and waves, and in the reefs extending from this to the shore, which 

 at low tide expose the beds very perfectly. It was first described in detail by the late Sir 

 W. E. Logan (Report Geol. Surv. Canada, 1844), and afterwards the middle portion of it 

 was still more detailed by the author (Dawson), more especially in connection with the 

 fossil remains characteristic of the several beds and the vegetable constituents and accom- 

 paniments of the numerous seams of coal (Jour. Geol. Soc. Lond., x, p. i, 1853). It was on 

 occasion of a visit of the author in company with Sir Charles Lyell, and in the pursuit of 

 these investigations, that one of the most remarkable features of the section was disclosed 

 in 1851. This is the occurrence, in the trunks of certain trees imbedded in an erect position 

 in the sandstones of Coal-mine Point, of remains of small reptiles, which with one exception, 

 a specimen from the Pictou coal-fields, were the first ever discovered in the Carboniferous 

 rocks of the American continent, and are still (1891) the most perfect examples known of 

 a most interesting family of coal-formation animals, intermediate in some respects between 

 reptiles proper and batrachians, and known as Microsauria. With these were found the 

 first-known Carboniferous land snails and millipedes. Very complete collections of these 

 remains have been placed by the author with his other specimens in the Peter Redpath 

 Museum and in the British Museum. 



"A forest or grove of the large ribbed trees known asSigillaria was either submerged 

 by subsidence or, growing on low ground, was invaded with the muddy waters of an inun- 

 dation, or successive inundations, so that the trunks were buried to the depth of several 

 feet. The projecting tops having been removed by subaerial decay, the buried stumps 

 became hollow, while their hard outer bark remained intact. They thus became hollow 

 cylinders in a vertical position and open at the top. The surface having then become dry 

 land, covered with vegetation, was haunted by small quadrupeds and other land animals, 

 which from time to time fell into the open holes, in some cases nine feet deep, and could 

 not extricate themselves. On their death, and the decomposition of their soft parts, their 

 bones and other hard portions remained in the bottom of the tree intermixed with any vege- 

 table debris or soil washed in by rain, and which formed thin layers separating successive 

 animal deposits from each other. Finally, the area was again submerged or overflowed by 

 water, bearing sand and mud. The hollow trees were filled to the top and their animal con- 

 tents thus sealed up. At length the material filling the trees was by pressure and the access 

 of cementing matter hardened to stone, not infrequently harder than that of the contained 

 beds, and the whole being tilted to an angle of 20, and elevated into land exposed to the 

 action of the tide and waves, these singular coffins present themselves as stony cylinders 

 projecting from the cliff or reef, and can be extracted and their contents studied. The sin- 

 gular combination of accidents above detailed was, of course, of very rare occurrence, and. 



