[MATTHEW] NEW GENUS OF BATRACHIAN FOOTPRINTS 83 



other species ; all of them have the print of the sole of the foot preserved. 

 The imperfection and irregularity of the track in H. Logani, which 

 by Sir Wm. Dawson himself is said probably to be that of an animal 

 partly water-borne, prevents one from using this as the type of the 

 genus; we therefore fall back on the second species as the one which 

 can be taken as a generic type. This species is H. Hardingi. 



The first reference we have to this fossil is in Lyall's Elements o.f 

 Geology (New York, 1866, p. 510), where the author says: " Footprints 

 of two reptiles of different sizes had previously been observed by Dr. 

 Harding and Dr. Gesner on ripple-marked slabs of the lower coal- 

 measures in Nova Scotia, evidently made by quadrupeds walking on 

 the ancient beach, or out of the water, just as the recent Menopoma is 

 ' sometimes observed to do." 



The footprints are again referred to in Dawson's Acadian Geology 

 (London, 1868, p. 356, with figures). Here Sir William says (p. 356) 

 that " Dr. Harding, of Windsor, when examining a cargo of sandstone 

 from Parrsboro, N.S., found on one of the slabs a very distinct series 

 of footprints, each with four toes, and a trace of a fifth. Dr. Harding's 

 specimen is now in the museum of King's College, Windsor. Its im- 

 pressions are more distinct, but not very different otherwise from those 

 found at Horton Bluff " [H. Logani.'] 



Aceording to " Air-breathers," (p. 9, Explanation of Plates, Fig. 2), 

 the figure of Hylopus Hardingi is from a rubbing taken by Professor 

 How, of Windsor College, and was evidently taken from the cast of the 

 fossil. Prof. How apparently failed to perceive and to indicate the 

 impression of the sole, or "heel," and so the drawing appears to be 

 taken from a digitate print, whereas the imprint shows plainly that the 

 animal rested on the sole of the foot as well as on the toes, in walking. 

 There is therefore no species of Hylopus in which the impression of the 

 sole is entirely wanting, except that of H. Logani, whose peculiar im- 

 pressions we have noted above. 



There is a marked advantage in the regularity as well as in the 

 distinctness of the tracks of H. Hardingi to the observer who wishes to 

 learn what the characteristics of the genus Hylopus are, for they show 

 distinctly the sole of the foot, and so approach a type of footmark com- 

 mon in the Carboniferous system. Hylopus, therefore, was made by 

 an animal which did not walk on the toes alone, but also pressed the 

 sole of the foot to the ground. 



Hylopus (as represented in the species H. Hardingi) clearly had 

 five toes to the hind foot, but the fifth toe of the fore foot is mis- 

 t-akenly shown. In his "Air-breathers," Sir William Dawson says (p. 7) : 

 " One pair of feet [the hind feet ?] appears to have had four claws ; 

 the other pair may have had three or four." So that the number of toe 



