108 THE UNIVERSITY SCIENCE BULLETIN. 



Tracks Nos. 7 and 8. (Plate 1, figs. 7 and 8.) These two tracks 

 were remov^ed in one block. The distance of stride from No. 6 to 

 No. 7 was two feet six inches. Here the animal changed its course 

 and turned sharply to the left, making a short step of only twelve 

 inches from track seven to track eight. Each of these tracks were 

 pressed firmly into the sandy matrix, making a bowd-shaped de- 

 pression, with sloping sides, twelve inches in diameter and six inches 

 deep. Grooves in the sides of the depressions show distinctly where 

 the toes and the pad of the front foot have pressed down to a depth 

 of four inches. At this level there is a slight ledge left where the 

 overlapping hind foot pressed still deeper down for another three 

 inches, leaving a well-defined imprint of the short claws and the 

 circular pits similar to those found at the base of the palm and sole 

 of the other tracks collected. 



Track No. 9. (Plate 1, fig. 9.) This, the last track of the series, 

 was situated two feet three inches from the preceding track, and 

 six inches higher in elevation. This probably is of the left side, but 

 whether of the manus or pes is rather doubtful. The imprint, being 

 on higher and drier ground, was less distinct and showed less char- 

 acter than those made in more plastic material. The bank rises 

 rapidly from the last track found, and although the overlying soil 

 was cleared away for quite a space around, no other indications of 

 tracks could be found. 



The finding of these scarce footprints in the Coal Measures of 

 Kansas will be welcomed because they may shed some light on the 

 ancestors of the later Permo-Carboniferous amphibians, or possibly 

 reptilian fauna of that age. 



Thanks are here expressed to the finders of these rare tracks for 

 their generosity in presenting them to the paleontological depart- 

 ment of the University of Kansas. 



I wish to express my thanks to Dr. Roy L. Moodie, College of 

 Medicine of the University of Illinois, to whom I am under obliga- 

 tions for assistance in the preparation of this paper. 



CONCLUSIONS. 



The present series of footprints referred to under the new term of 

 Onychopus gigas indicates one of the largest, if not actually the 

 largest, pre-Triassic vertebrate thus far known from the geological 

 horizons of the world. A short-bodied, long-limbed vertebrate with 

 well-developed feet left these impressions, of whose bodily structure 

 nothing whatever is known. So deeply marked are the footprints 



