MARTIN: A GIGANTIC AMPHIBIAN. Ill 



EXPLANATION OF PLATE I. 



The small figures on the left, from 1 to 9, indicate the series of amphibian 

 footprints in the sandstone ledge of the Upper Coal Measures. After makmg 

 the sixth impression the animal turned sharply to the left, so that the drawing 

 does not represent exactly the manner of occurrence. It shows, however, the 

 distance between impressions. No. 1 is possibly a fore-foot impression, with 

 portions of another; No. 2, the left pes; No. 3, the left manus; No. 4, indefi- 

 nite; No. 5, left pes; No. 6, left pes, part manus; No. 7, left pes, part left 

 manus; No. 8, left pes, part manus; No. 9, undecided. 



The figures 2 to 10 on the right of the plate are detailed studies of the 

 best-preserved tracks. 



No. 2, left pes with a distance of 130 mm. across the heel impressions at 

 the level of digit I. The distance between the tips of digits I and II, II and 

 III, III and IV is in each case 40 mm.; between IV and V is 80 mm. Small 

 pits in the heel impression indicate heel pads. 



No. 3, left manus. The small pits to the left indicate toe marks of another 

 foot. The greatest width of this foot is 105 mm. The distance between the 

 tips of digits I and II, II and III is in each case 50 mm.; between III and IV 

 is 40 mm. 



No. 4, right manus. The distance from the tip of digit III to the posterior 

 edge of the heel pad is 95 mm.; between II and III, 45 mm.; between I and 

 II. 4S mm. 



No. 5, right pes. The greatest length is 110 mm.; the greatest width 

 120 mm. 



No. 6, undoubtedly a pes, with well-marked heel pads. The greatest length 

 is 140 mm., the greatest width 144 mm. 



No. 7, a pes. The impressions below the pes represent a second impression, 

 which was probably obliterated by the hind foot. The circle surrounding the 

 footprints represents the edge of a three-inch depression in which the foot- 

 prints occurred. This indicates both the great weight of the animal and the 

 softness of the ground. 



No. 8, a part of pes and manus, also occur in a depression three inches 

 deep. 



No. 9 shows two superimposed impressions of a fore and a hind foot. The 

 greatest width of the hind foot is 135 mm. 



No. 10 is a sketch of the appearance of the depression, showing the shape 

 of the depression and the long furrows made by dragging blunt claws along a 

 moist surface. Claws have been previoush^ indicated in the remains of the 

 larger Permian and Triassic amphibians, in the presence of blunt terminal 

 rugose phalanges, but so far as I am* aware no impressions of them have been 

 so clearly recorded in the rocks of the Coal Measures. 



