THE FOSSIL FOOTMARKS OF THE UNITED STATES. 195 



Species 5. Ornithopus rectus. (PI. V. Fig. 4.) 



Nos. 244, 245, in Cabinet. 



Divarication of the front lateral toes, 75° to 80° ; of the inner and 

 middle toes, 40° ; of the middle and outer toes, 40° ; of the inner 

 and hind toes, 40° to 60°. Length of the hind toe, 1.8 inch ; of 

 the inner front toe, 2.7 inches ; of the middle front toe, 3.5 inches ; 

 of the outer toe, 2.9 inches ; of the middle toe beyond the rest, 

 1.4 inch; of the foot, 4.6 inches; of the step, 18 inches. Heel 

 rather broad, and extending back farther than the hind toe. Dis- 

 tance between the tips of the hind toe and the middle front toe, 4 

 inches ; between the second and middle toes, 2.2 inches ; between 

 the middle and outer toes, 2.4 inches ; between the second and 

 outer toes, 3.6 inches ; between the rows of tracks, 7 inches. Axis 

 of the foot nearly coincident with the line of direction. Track 

 shown, of the natural size, on Plate 5, fig. 4. 



Locality. — Horse Race, Gill ; at the quarry, three miles above 

 Turner's Falls ; on gray micaceous sandstone. 



Remarks This species was discovered while this paper was 



passing through the press. The quite distinct specimens on which 

 it is founded were presented to me by Mr. Ptolemy P. Severance, 

 who has charge of the quarries and public works at Turner's Falls. 

 I was in doubt whether to refer this species to Ornilhopus or Plec- 

 tropus ; but the shortness of the heel and the nearness of the roots 

 of the hind toe to the roots of the others have led me to place it 

 as a fifth species of the former. In the great distance between the 

 tracks of the right and left foot, it differs from all other species ex- 

 cept the Harpedactylus concameratus ; and one cannot but inquire 

 whether possibly the animal was not a quadruped, moving forward 

 like the Proteus, as described in another part of this paper. At 

 present, however, the evidence is very slight of a quadrupedal char- 



