New Genera of Batrachian Footprints. 101 



somewhat more than the others. The sole projects back- 

 ward in a prolonged heel. 



This form of footmark is not uncommon on the layers 

 at the Joggins, and, like Hylopus, had often a rough sur- 

 face, perhaps owing to the sharp claws with which the 

 toes were furnished. It is necessary to separate it from 

 Hylopus, because there are the impressions of only three 

 toes to the fore foot, and because of the distinct impres- 

 sion of a sole to both fore and hind foot. The fact that 

 there were only three toes to the fore foot also separates 

 it from a number of genera that have been described by 

 authors. On comparing the fore foot with the hind, it 

 will be seen that the obsolete digits of the fore foot are 

 probably the first and second. 



The irregularity of the foot print in some species of 

 this genus shows the flexibility of the toes, and the name 

 of the genus alludes to the rough and irregular imprints 

 left by animals of this kind. 



Asperipes avipes n. sp. (PI. Figs^ 3« and Sb), is the type 

 of this genus. Two other species are known. 



It might be thought that in Asperipes the footprint 

 showing the marks of only three toes is that of the hind 

 foot. In many mammals, and in the alligator among the 

 reptiles the foot with fewest toes is the hind foot. The 

 long heel also of the footmark, determined as the fore 

 foot, is a mark of the hind foot in many dinosaurs, as, for 

 instance, in Anomepus and Otozoum, and it is therefore 

 necessary to explain why it is supposed this anomalous 

 relation of the two footmarks exist in Asperipes. We 

 have not seen any consecutive series of footprints of the 

 type species that will determine this relation, and the 

 determination is based on the relation found to exist in 

 the footprints of the other two species. 



In the second species the disparity in size between the 

 print of the fore and hind foot is somewhat greater than 

 it is in the type species, in which we see some indication 

 that the three-toed footmark, being the smaller, is that of 



