62 THE CARBONIFEROUS. 



characteristic to warrant any confident statement on the subject. 

 These coprolites must have been produced by Dendrerpeton or 

 Hylerpeton, most probably the former. 



hi the summer of 1877 Mr Hill kindly extracted for me three 

 other trees which had appeared in the reptiliferous bed, but they 

 proved barren of reptilian remains, though affording some curious 

 fossil plants. A fourth, which presented great difficulties in its 

 extraction, being 2\ feet in diameter, and embedded in sand- 

 stone to the height of 8 feet, was taken out for me in the same 

 summer. It afforded only one skeleton of Dendrerpeton and de- 

 tached bones of Hylonomus, but was interesting as showing on one 

 layer the trails and tracks left by a reptile dragging itself around the 

 sides of the hollow tree in its efforts to escape. The details of all 

 these discoveries I hope to give to the public so soon as I can take 

 time to study fully the bones and teeth obtained. 



I think it quite possible that further examination may enlarge the 

 number of species above mentioned. I have been guided mainly in 

 the reference of the specimens to species by the structure of the teeth 

 and the cranial bones ; but some of these may yield new points of 

 difference on further study. As all the specimens are preserved under 

 the same conditions, there is less liability here than in most cases 

 to multiply species unduly, in consequence of different states of 

 preservation. 



The fact that Cope has been able to catalogue, in his recent Report,* 

 39 genera of Carboniferous batrachians, including about 100 species, 

 and that these present so wide a range of size, structure, and general 

 conformation, affords a very remarkable illustration of that simul- 

 taneous occurrence of many forms of one type, which appears in so 

 many other groups of fossil animals ; and is particularly striking in 

 this first known group of air-breathing vertebrates, which since 1843 

 have swarmed upon us from the Coal-fields of both continents, and of 

 which we probably know as yet but a small fraction of the species. 

 It remains to be seen whether the Devonian, so rich in its land flora, 

 and which has already afforded remains of insects, may not disclose 

 some precursors of the Carboniferous batrachians. 



Since the publication of the second edition, some very interesting 1 

 discoveries of footprints of Carboniferous reptiles have occurred. 

 The most important of these is that originally made by Mr Albert 

 J. Hill, C.E., at Fillimore's quarry, near River Philip. At this place 

 certain beds of brownish red sandstone hold numerous footprints of a 

 large batrachian, now in the collection of the Geological Survey of 



* Palaeontology of Ohio, vol. ii. 



