THE FOSSIL FOOTMARKS OF THE UNITED STATES. 205 



Nos. 7-12, 157, 160, 162, 165, 169, 177, in Cabinet. 

 Divarication of the lateral toes, 50= ; of the inner and middle 

 toes, 25° ; of the middle and outer toes, 25'^ ; of the middle and 

 hind toes, 115°. Hind toe proceeding from the extremity of the 

 heel. Length of the middle toe, 2.3 to 3 inches ; of the inner 

 toe, 1.5 to 2 inches ; of the outer toe, 1.5 to 2.2 inches ; of the 

 hind toe, 0.7 to 1 inch ; of the heel, 0.3 to 0.5 inch ; of the middle 

 toe bejond the rest, 1.1 inch ; of the foot, 2.8 to 3.6 inches. Dis- 

 tance between the tips of the lateral toes, 1 .5 to 2 inches ; be- 

 tween the inner and middle toes, 1.1 to 1.5 inch; between the 

 middle and outer toes, 1.3 to 2 inches; between the middle and 

 hind toes, 2.9 to 3.9 inches. Heel 0.2 inch wide ; at the roots of 

 the front toes, 0.4 inch. Versed sine of the inward curvature of 

 the inner toe, 0.15 inch; of the same in middle toe, 0.1 to 0.15 

 inch ; of outer toe, outwards, 0.05 inch. Track shown, of the nat- 

 ural size, on Plate 10, fig. 5. 



Locality. — Wethersfield, at the Cove; on red shale, intermingled 

 with the last species. 



This species is dedicated to Professor Ebenezer Emmons, of 

 Albany. 



No. 7 (Cabinet) furnishes us with an instructive example of a 

 change of form in the track of this species, as it appears on succes- 

 sive layers of litde more than an inch in thickness. Plate 15, 

 fig. 14, shows the track on the uppermost layer ; fig. 15, on the 

 second; and fig. 16, on the lowest. 



Remarks. — Although my specimens of the tracks of this and 

 the preceding species are more numerous than of any other, and 

 most of them as perfect impressions as can be made on a plastic 

 material, I have not been able to ascertain the length of the step, 

 nor, in fact, to satisfy myself whether the animal was a biped or a 



