Section IY., 1903 [ 109 ] Trans. R. S. C. 



lY. — An aitempt to classify Palœozoic Batracliian footpnnts. 

 By Dr. G. F. Matthew. 



(Read May 21st, 1903.) 



Having had occasion to seek generic names for certain Batraehian 

 and other footprints obtained at the Joggins shore in Nova Scotia, which 

 have Just been described in the Bulletin of the Natural History Society 

 of New Brunswick, I was surprised at the diversity of usage which 

 prevails in the application of generic names to these impressions. 



The name Sauropus was used by Lea in 1849 for a common form of 

 track of the coal measures, and was applied by Dr. J. W. Dawson and 

 others to footmarks of the Palœozoic. But Dr. 0. P. Hay says this name 

 was given to tracks of Triassic age by Hitchcock, (presumably at an 

 earlier date), he therefore substitutes Palseosauropus for all the Carboni- 

 ferous tracks called Sauropus by authors. 



This claim of the inapplicability of Sauropus to the Palaeozoic forms 

 is not without reason, for undoubtedly the animals which made the foot- 

 marks on the Carboniferous mud flats were of different genera from those 

 which wandered along the shores of Triassic estuaries. 



But as the forms which bear the name of Sauropus, and were pro- 

 duced on the Carboniferous flats are quite diverse from each other, they 

 cannot all come under one generic name, of Palseosauropus; Sauropus 

 primœvus of Lea, for instance, is quite different from S. Sydnensis of 

 Dawson. Other species included under Palseosauropus can with advant- 

 age be included under generic names given by other writers, previous to 

 the publication of Dr. Hay's list. 



For the type of footmark represented by Sauropus primœvus, no 

 less than four different generic names have been used, these being given 

 to as many different species, these are Th.enaropus, Notolacerta, Anthra- 

 copus and Sauropus. And a similar diversity of generic names may be 

 found in several other groups of thc'se footprints. 



To find a common basis of classification is difficult. There is sug- 

 gested as a primary division the grouping into IJrodela and Anoura of 

 the recent Amphibians; but setting aside the fact that the relation be- 

 tween the Labyrinthodonts (which probably made most of the Palaeozoic 

 footmarks), and the orders of modern Amphibians above named, is a 

 distant one, the impression of the tail in these tracks where it does occur 

 is very unreliable. In some the supposed print of the tail is so heavy, 

 as to raise the suspicion that some other marking has been mistaken for 

 it ; in others the trail occurs intermittently, and in others it occurs in an 

 impossible relation. 



