102 ROYAL SOCIETY OF CANADA 



jpreserved, and there are two prints each of the hind and the fore foot 

 of that side. 



The track is on a firm, fine grained gray sandstone ; a thin film of 

 mud on the sand preserved accurately the impression of the footmarks, 

 and of striae made by seaweed, etc. 



Megapezia.i 



The peculiar shape of the print of the hind foot appears to separate 

 this from any described genus, though there is a figure given by King in 

 American Journal 'Science, without any name attached, which, in its 

 very large sole, may be compared to Megapezia; that, however, is repre- 

 sented as having five toes to the hind foot, while in this new genus there 

 are only four. Yet while the number of toes on this foot is four, that 

 on the fore foot is five; it thus reverses the number of toe prints of the . 

 hind and fore foot, usually ohserved in such Palaeozoic footprints as have 

 nine toes on the two feet collectively. To this relation, in the num- 

 ber of the toe prints; but we have a parallel in the footprints of the 

 alligator, which also has four toes on the hind and five on the fore. The 

 resemblance extends to the attitude of the toes, which are turned forward 

 in the hind foot, but radially arranged in the fore foot. There is this 

 distinction, however, that the peculiar backward curve of the fifth digit 

 of the hind foot in j\fegapezia is not found in the alligator. 



In the hind foot of Megapezia the fifth digit sets off from the others, 

 and the end is strongly curved backward. The toes axe rather short 

 and blunt (though perhaps having claws) ; the second, third and fourth 

 digits are somewhat grouped, and directed forward and the first appears 

 to be the digit that is wanting. The sole of the foot is large, but not 

 heavily impressed. 



The fore foot has a short and weak fifth digit, and the others are 

 progressively shorter than the first; they are proportionately longer 

 than those of the hind foot. The sole is short, except behind the fourth 

 and fifth digit, where it extends into a long heel somewhat as in 

 Asperipes. 



These animals were of good size and had a, long stride, so perhaps 

 were active in their habits, and as the impression on firm sand was 

 strong, they would have been rather heavy animals. 



The type is Megapezia Pineoi of the Lower Carboniferous measures 

 at Parrsboro, N.S. (Can. Eec. Sci. PL, Figs. 2a and 26), and the generic 

 name is in allusion to the large size of the sole of the hind foot. 



In this genus the usual signs seem to designate without doubt 

 which is the hind and which the fore foot. First the larger size of the 



' Can. Rec. Sci., Vol. IX., No. 2, p. 107, 1903, Montreal. 



