THE FOSSIL FOOTMARKS OF THE UNITED STATES. 219 



4.2 inches. Rudiment (?) of the fifth toe shown by a protuber- 

 ance on the inside of the heel. Breadth of the heel, or hind part, 

 2.7 inches ; of the toes, from 0.6 to 0.9 inch. Distance from tip to 

 tip of the lateral toes, 4.5 inches; of the first and second, 1.5 inch ; 

 of the second and third, 1.8 inch; of the third and fourth, 2 inches. 

 Toes blunt. Angle between the axis of the foot (a line drawn 

 from the extremity of the heel to the middle point between the 

 second and third toes) and the line of direction, 35°. 



Hind foot. — Five toes, with the rudiment of a sixth (?) on the 

 inside. Divarication of the outer toes, 75° ; of the inner and 

 second, 15°; of the second and third, 20°; of the third and fourth, 

 10° ; of the fourth and fifth, 28°. Length of the inner toe beyond 

 the web, 1.6 inch; of the second, 1.8 inch; of the third, 2.4 

 inches ; of the fourth, 3.1 inches ; of the fifth, 0.9 inch ; of the 

 foot, 5.5 inches ; of the step, 9 to 16 inches. Distance between 

 the hind and fore feet on the same side, to 1 inch. Angle of the 

 axis of the hind foot with the line of direction, 0° to 30° ; usually 

 coincident. Distance between the two rows of tracks, 6 to 8 

 inches ; between the tips of the lateral toes, 4 inches ; between 

 the first and second, 1.2 inch ; between the second and third, 1.5 

 inch; between the third and fourth, 1.2 inch; between the fourth 

 and fifth, 3.2 inches. Width of the heel, about 2.2 inches. 

 Tracks of the fore and hind foot shown, of the natural size, in 

 a normal position, on Plate 16, figs. 1, 2. 



Remarks. — The tracks of this animal were first described by 

 Dr. Alfred T. King, in the Proceedings of the Academy of Natural 

 Sciences, Philadelphia, for November and December, 1844, and in 

 the American Journal of Science, Vol. XLVIII., p. 348. They oc- 

 cur in Westmoreland county, Pennsylvania, in the rocks of the coal 

 formation, about 800 feet below its top. The sketch, Plate 16, 



