108 Canadian Record of Science. 



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 ; 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. (PI., Figs. 2a and 2b), 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 sole in the foot bearing four toes 

 shows that the weight of the body was born by this foot. 

 The smaller number of toes and the forward direction of 

 three point to a greater specialization of this limb for 

 walking, &c. 



On the other hand the full number of digits on the fore 

 limb and the radial arrangement of the toes point to a 

 varied use of this limb, for prehension as well as for 

 walking, for which latter purpose it seems to have been 

 habitually used. Every feature appears to point to this 

 as the print of the fore foot of the animal. 



If it be such, however, one cannot fail to note the 

 strong resemblance between this which we have deter- 

 mined as the fore foot of Megapezia, and that which 

 appears to be the hind foot of Asperipes. This is obvions 

 on comparing Figure 2b of Plate with Figure 3a of the 

 same plate. 



It may be thought that we attach too much importance 

 to the size and weight of the footmark as determining 

 which marks were made by the fore, and which by the 



