THE FOSSIL FOOTMARKS OF THE UNITED STATES. 207 



the mud as the animal walked. Toes all curved inward. Versed 

 sine of the hind toe, 0.12 inch ; of the inner front toe, 0.17 inch ; 

 of the middle toe, 0.13 inch; of the outer toe, 0.2 inch. Angle 

 between the axis of the foot and the line of direction very large. 

 Axis of the heel prolonged strikes the tip of the outer toe. Middle 

 front toe making an angle with that axis of 40°. Inner toe making 

 a similar angle equal to 70°. Fourth toe making an angle equal to 

 60°. Toes, particularly the posterior, extremely narrow. Track 

 shown, of the natural size, on Plate 14, fig. 2, copied from a quite 

 perfect specimen in Mr. D. Marsh's cabinet, lately found by him 

 at Turner's Falls. Plate 20, fig. 1, shows two tracks, in their nor- 

 mal position, from the same locality, reduced from their natural 

 size three times. 



Localities. — Turner's Falls, Horse Race, and Wethersfield. 



Remarks. — Although I described this species in my Report on 

 the Geology of Massachusetts, yet so defective were my specimens, 

 that I despaired of giving it a place in this paper, until the discovery 

 of the specimens from which the preceding figures were drawn. 

 One cannot look at these, without feeling a strong impression that 

 the animal will prove to be a quadruped ; and facts which I have 

 yet to mention, as to the small fore feet of some animals having 

 often made only a slight impression on mud, lead to the suspicion 

 that such may be discovered in connection with these. If, indeed, 

 Plate 14, figs. 4 and 5, sketched from a specimen presented to me 

 by Dr. Deane, and found at Turner's Falls, belongs to this species, 

 as I rather presume it may, it shows us the hind and fore feet. 



Species 2. Harfedactylus concameratus. (PI. XIV. Fig. 3.) 



No. 1 80 in Cabinet. 



Tridigitate. Divarication of the lateral toes, 60^ ; of the inner 



