82 ROYAL SOCIETY OF CANADA 



Without a more careful examination and comparison of these foot- 

 marks the writer is not prepared to make a generic reference; though 

 if Hylopus is -limited as in the following pages, this species must go 

 elsewhere as having five toes on each foot and a large sole to the hind 

 footmark. 



Hylopus, Dawson, 



PI. I, fig. la, h. PI. VI, figs. 1 and 2. 



Sir Wm. J. Dawson describes the several footprints of quadrupeds 

 of the Carboniferous age obtained from the Joggins, Parrsboro, Horton 

 and Sydney, Nova Scotia, under the two genera, Sauropus and Hylopus. 



The latter genus being Dawson's own, it behooves us to examine 

 the types and learn what its characters are. He defined the genus 

 Hylopus as follows : " Smaller footprints [than Sauropus, Lea] Digiti- 

 grade, and made by animals having a long stride, and hind and fore 

 feet nearly equal. Five toes. Probably footprints of Microsauria, and 

 possibly of Dendrepeton." ^ 



This genus was based upon three species described in Sir William's 

 " Air-breathers of the Coal Perio-d," - and figured in the same essay, 

 but not then named; in the later essay they have names given them, 

 and an additional species is descril^ed. There is so much variation in 

 the form of those footprints that they cannot all be contained in the 

 genus Hylopus, and it becomes necessary to select a type or types to 

 represent the genus. There are two forms which appear to come nearer 

 the ideal of Dawson's genus than the others, these are H. Logani and 

 H. Hardingi. 



It would appear from the figures given in the " Air-breathers " that 

 both of these species were described from casts, one of which, H. Logani, 

 is in the Eedpath Museum, Montreal, the other, H. Hardingi, in that of 

 King's College, Windsor, N.S. Both species are of Lower Carboni- 

 ferous age, and come from measures underlying the Carboniferous lime- 

 stone. The author has been favoured with an opportunity to examine 

 both of these casts, and so has seen the objects on which Sir William 

 has based the genus Hylopus. 



The series of footmarks which are the type of H. Logani, are sup- 

 posed by Sir William to have been made in soft mud by an animal partly 

 wiater-borne, and they are decidedly " digitigrade," in some cases only the 

 long middle toes scrape the surface of the mud, and were not impressed 

 upon it, and in the most distinct only the toe marks are preserved, hence 

 the track is truly digitigrade. But this is not the case with ajiy of the 



^ Trans. Roy. Soc. Canada, Vol. XXII., Sec. IV., p. 77, 1894. 



' A'ir-brea'thers of the Coal Period of Nova Scotia, Montreal, 1863 



