THE FOSSIL FOOTMARKS OF THE UNITED STATES. 193 



Localities. — Horse Race, Gill ; Chicopee Falls ; and Wethers- 

 field, at the Cove. 



Remarks. — By comparing Plate 7, fig. 1, with Plate 17, fig. 4, 

 leaving out the hind toe of the latter, the force of the remark 

 already made, that the Platypterna Deaniana may be only the 

 Ornithopus gullinaceus divested of the hind toe, will be appreci- 

 ated. And we know that the hind toe frequently disappears. 



Species 3. Ornithopus gracilior. (PI. VIII. Fig. 2.) 



Ornithoidichnites gracilior j Mass. Geol. Rep., Plate 46, fig. 43. 



Nos. 118, 119, 208, in Cabinet. 



Divarication of the lateral toes, 75° to 90° ; of the inner and mid- 

 dle toes, 40° ; of the outer and middle toes, 35° to 60° ; of the 

 middle and hind toes, 110° to 130°. Length of the middle toe, 

 1.5 inch; of the inner toe, 1.1 inch; of the outer toe, 1.1 inch. 

 Hind toe digitigrade, articulated high upon the tarsus ; length of 

 the same from the roots of the toes, 0.8 inch ; of the part that 

 impresses the ground in walking, 0.3 to 0.5 inch. Middle toe 

 rather keel-shaped. Toes nearly straight. Length of the foot, 

 excluding the hind toe, 1.4 to 1.7 inch ; of the middle toe beyond 

 the rest, 0.7 inch. Distance between the tips of the lateral toes, 

 1 .7 inch ; between the inner and middle toes, 1 .05 inch ; between 

 the middle and outer toes, 1 .3 inch ; between the middle and hind 

 toes, 2 inches. Track shown, of the natural size, on Plate 8, 

 fig. 2. 



Locality. — Wethersfield. 



Species 4. Ornithopus loripes. (PI. VIII. Fig. 3.) 



Ornithoidichnites divaricatus, Mass. Geol. Rep., Plate 44, fig. 36. 

 Nos. 95, 97, 101, 102, 121, 143, in Cabinet. 

 26 



