50 SMITHSONIAN MISCKLLANEOUS COLLECTIONS VOL. 8o 



of relative proportions as shown in the table of comparative measure- 

 ments, and especially by Dawson's original determination, it would 

 seem there can be but little doubt that the creature making the tracks 

 called Hylopus hardingi had five digits on the forefoot. The liability 

 of toes not to impress is clearly shown in the specimen now before 

 me for although in most of the tracks forming this short trail all 

 toes are indicated, one hindfoot impression shows only the dimmest 

 record of digit four and no trace at all of the outer toe. 



Hylopus hcnnitaniis most closely approaches H. hardingi in size 

 and arrangement of the digits of the feet, but may be distinguished 



Fig. 2T). — HylopHs hardingi Dawson. Fore- and hindfoot of left 

 side. Natural size. (After Matthew.) 



from that species by the more widely separated and more divergent 

 toes, and especially by the more forward position of the fifth toe. 

 In both //. hdrdingi and H . minor, the fifth toe is given ofif far back 

 on the side of the sole. In the forefeet of both of these species the 

 lateral toes are much less divergent than in the specimen here de- 

 scribed (compare figs. 21 and 22). 



In offering conjectures about the known animals which might have 

 been responsible for the Nova Scotian tracks. Sir William Dawson 

 suggests they may have been made by some microsaurian-like Hyler- 

 pcton or Hylonomus. In any event, all of the tracks here discussed 

 seem to conform more nearly to those made by amphibians than to 

 those of any known reptile. 



