120 ROYAL SOCIETY OF CANADA 



•usually single or a single pair, they are in form characteristically Batra- 

 chian, as much so as the recognized Batrachian footprints of the Car- 

 boniferous. 



The intimate association of these footprints with remains of freshly 

 fallen leaves and stems of plants, would lead to the inference that the 

 animals which made them had a terrestrial or arboreal habitat. Tt seems 

 possible as the author has elsewhere suggested that the tracks were made 

 hy Batrachian animals that were seeking the margins of pools or rivers 

 in search of food, or for other purposes. 



That animals of this comparatively high type of structure may have 

 lived in Silurian times, seems not improbable when we consider that the 

 vegetation of this time was so exceedingly like that of the Carboniferous 

 that palœophytologists of the highest renown have not hesitated to assert 

 that the associated plants are Carboniferous. 



Two of the t}T)es of footprints described below are of Carboniferous 

 or Upper Devonian genera, but the third appears to be peculiar to this 

 terrane. 



DESCRIPTION OF THE SPECIES. 



Hyi.opus ( ?,) VAKiABiLis n. sp. Plate II, Figs. 1 to 3. 



One of these tracks I refer provisionally to the above genus of Sir 

 Wm. Dawson, as it comes near to that type in the form of the footprints 

 and the number of impressions of the toes. 



In the irregular position of the toe-prints and the absence of the 

 pairing together of the hind and fore footprints which is common in 

 Hylopus it is more like Asperipes, but I do not find it to be character- 

 ized by three toe-prints on one of the feet, which is a character of the 

 latter genus ; it is therefore placed provisionally under Hylopus. 



Hind ( ?) foot " plantigrade " with a short, broad palm. Toe-prints 

 five in number regularly spread, increasing in length from the first to 

 the fourth where the palm is most extended forward, the fifth is shorter 

 than the fourth and set on the side of the palm ; there is a callus or lump 

 on this side of the palm at the back. 



In the fore (?) foot, of the four toes of which impressions are found 

 the toes are widely spread; the two inner ones are of equal length and 

 directed inward, the next (4th digit) is short and directed forward, the 

 'next outward (5th digit) is prominently directed outward. 



Size. — Hind ( ?) footmark, length, 25 mm. ; width, 28 mm. Fore 

 footmark ( ?), length, 13 mm.; width, 24 mm. 



Stride (in another example), 70 mm. 



Straddle unknown as there are only two footmarks of one side 

 known. 



