THE FOSSIL FOOTMARKS OF THE UNITED STATES. 213 



Nos. 131 - 133, in Cabinet. 



Divarication of the lateral toes, 35° ; of the inner and middle 

 toes, 20°; of the middle and outer toes, 15°. Length of the middle 

 toe, SO far as it usually impresses the ground in walking, 1.9 inch ; 

 whole length of do., 2.8 inches ; of the inner toe, 1.3 inch ; of the 

 outer toe, 1.8 inch; of the part of the heel running directly back- 

 ward, 0.7 inch ; of the lateral part, 2 inches ; of the foot, 4 inches ; 

 of the step, 18 inches ; of the middle toe beyond the rest, 1.4 inch. 

 Width of the heel, 0.2 to 0.3 inch ; of the foot at the roots of the 

 toes, 2.2 inches. Distance between the tips of the lateral toes, 2.8 

 inches ; between the inner and middle toes, 1.8 inch ; between the 

 middle and outer toes, 2 inches. Axis of the left foot turned in- 

 ward from the line of direction, 15° ; of the right foot, 30°. Dis- 

 tance of the axis of the foot from the line of direction, 2.5 inches. 

 Right foot shown, of the natural size, on Plate 10, fig. 6. Plate 

 I9, fig. 7, shows three tracks in their normal position, one sixth of 

 the natural size (linear measure), sketched from a slab in the cab- 

 inet of Mr. Dexter Marsh. 



Locality. — Turner's Falls. 



Plate 15, fig. 2, is copied from a very distinct specimen of foot- 

 marks from Wethersfield, and seems to approach the Typopus in 

 form, though a distinct species. But I hesitate to describe it as 

 such, because, being near another track, its form may have been 

 altered, and I have only one specimen. 



Remarks. — All the specimens yet found show the extraordi- 

 nary fact, that the right foot has a divergence of 15° more than 

 the other from the line of direction ; and especially the specimen 

 in Mr. Marsh's collection, from which Plate 19, fig. 7, was copied. 

 This surely cannot be natural, if the animal was a biped ; for na- 

 ture, with few exceptions, constructs pairs of organs alike. What 



