MARTIN: A GIGANTIC AMPHIBIAN. 107 



ridges as one would expert if the animal had separate unwcbbed 

 phalanges, but in a smooth, rounding ridge, indicating that either a 

 fleshy pad, or more likely a thick web, extended to the base of the 

 short, blunt claws. The hinder part of the impression has un- 

 fortunately eroded away, so that no imprint of the heel is retained. 

 Both the manus and the pes are represented here, and naturally that 

 of the pes shows most distinctly. Towards the hinder part of the 

 impression there is a small, round indentation, as if caused by a 

 conical protuberance beneath the pad of the foot, as indicated in 

 other tracks of the series. The elevation from the first track to the 

 second is three feet. 



Track No. 3. (Plate I, fig. 3.) This track was exactly two feet 

 from its predecessor, measurements in each instance being made 

 from the centers of the impressions. There are four distinct toe 

 marks in this track, evidently a left manus. This track, like No. 2, 

 was' in a shelving, badly eroded place, leaving no imprint of the 

 palm. From this track to No. 9, the last in the series, there is 

 an elevation of 3 feet. 



Track No. 4. (Plate I, fig. 4.) This impression was separated 

 by eight feet of clear space from No. 3, and it has the least charac- 

 ter of any in the set. There are four light toe marks, and two of 

 the small, round depressions at the base of the palm. These were 

 made, no doubt, by round, warty tubercles beneath the foot. The 

 relative position of the toe imprints to each other indicates a right 

 manus, but so indistinct are the surface toe marks that it is doubtful 

 if the}' do not belong to the left instead of the right. 



Track No. 5. (Plate I, fig. 5.) From the fourth to the fifth track 

 there is a space of ten feet, covered to a depth of several inches with 

 soft mud and yet unexplored. Future rains will doubtless disclose 

 more impressions. Track No. 5 shows deep scoring on the edges 

 of the depressions by the slipping of the claws. The four grooves 

 thus made end with the same number of round pits, pressed a half 

 inch or more below the level of the palm, while at the base of the 

 palm one of the small circular pits occurs. These small pits appear 

 at the base of each palm and sole wherever the conditions are fav- 

 orable enough to retain the imprint of the hinder part of the foot. 

 There is no doubt but that this track represents the impression of 

 the left manus. 



Track No. 6. (Plate 1, fig. 6.) Impression No. 6, two feet six 

 inches from No. 5, is similar in all respects to others already de- 

 scribed, and is the left pes. 



