Principal Dawson — On Sauropiis unguifer. 253 



These footprints must have been made on a subaerial surface, prob- 

 ably left dry by the recession of the tide, and rain must have fallen 

 shortly before the animal passed over it, as indicated by the pitted 

 appearance of the slabs. The trunk of the creature may have been 

 three feet in length. Its tail, if it had such an appendage, must 

 have been short or carried in the air without touching the ground. 

 Its legs were strong, and bore the body well above the surface when 

 walking. The only known Carboniferous batrachian of Nova Scotia 

 which could have made these impressions is Baphetes planiceps, 

 Owen, discovered by the author in the coal-field of Pictou. 

 Eosaurus Acadiensis, of Marsh, from the Joggins, was a creature 

 of sufficient size, but probably of different structure, and more 

 exclusively aquatic habits. 



The principal distinctive character of the present specimens is the 

 peculiar appendage on the hind foot, and from this we may give the 

 provisional name Sauropus unguifer to these footprints, until the 

 animal which produced them shall be known to us by its bones. 



It is interesting that in three localities in Nova Scotia, and two in 

 Pennsylvania, footprints of this general type and of the same size 

 have been found, indicating the wide diffusion and abundance of 

 these large batrachians in the Carboniferous period in North 

 America, and also that they were animals comparable in size and 

 development of limb with some of their successors in the Mesozoic 

 period. 



One of the slabs in the rooms of the Survey shows a number of 

 less distinct footprints of an animal which may have been two- 

 thirds of the size of that above described, though possibly of the 

 same species. 



On another slab, and associated with the larger footprints, are 

 some small trifid impressions which seem to indicate the presence of 

 a still smaller animal, with feet of different form from those of the 

 others. These small trifid footprints are not dissimilar from those 

 found by Sir W. E. Logan, at Horton, in 1841, and which were the 

 first indications of reptilian life discovered in the Carboniferous. 

 They are also allied to those subsequently discovered by Dr. Harding 

 at Parboro', and by myself at the Joggins, and referred to in Acadian 

 Geology, These smaller footprints, showing marks of three toes, 

 and in more distinct impressions of four or five, I have conjectured 

 may have been produced by Labyrinthodonts of the type of Den- 

 drerpeton. 



In addition to the slabs above referred to, there is another in the 

 possession of S. Fleming, Esq., C.E., in Ottawa, of which I have 

 seen a photograph and which is reproduced in the accompanying 

 woodcut. It contains a good series of Sauropus unguifer, aloove 

 described, and shows best the equidistant character referred to 

 of some of the impressions. 



