182 AN ATTEMPT TO DESCRIBE THE ANIMALS THAT MADE 



Group II. 



Characters. — Tridact^'lous, leptodactjlous, bipedal, vertebrated. 



Germs I. STEROPEZOUM. 



Toes somewhat keel-shaped; the middle' and inner ones curved 

 towards the line of direction ; the outer one slightly bent from that 

 line. Heel distinct and large ; leaving an impression on mud of 

 radiating ridges and furrows, sloping upwards very gradually be- 

 hind, more abruptly before, leaving a ridge on the track, at least 

 as high as the general surface, between the heel and the toes, which 

 also slope upwards posteriorly. This ridge, however, has usually 

 a depression in it, connecting the heel and the outer toe. But, 

 upon the whole, we infer that the foot arches upwards between the 

 toes and the heel, leaving, however, a slight ridge along its outer 

 part. Bottom of the heel a little elevated above that of the toes. 



Remark. — Of the nature of that structure of the heel, which 

 produces on the track radiating ridges, somewhat resembling fine 

 ripple-marks, I feel in doubt, yet am inclined to believe them the 

 result of rugosities, or striae and ridges on the heel. 



Species 1. Steropezoum ingens. (PI. V. Fig. 1.) 



Ornithichnites ingens, Am. Jour. Science, Vol. XXIX. p. 319. 



Ornithoidichnites ingens, Mass. Geol. Rep., Plate 40, fig. 27. 



Nos. 63 - 66 in Cabinet. 



Divarication of the lateral toes, 60° ; of the inner and middle 

 toes, 35° ; of the middle and outer toes, 25°. Length of the mid- 

 dle toe, 13 inches ; of the inner toe, 9.75 inches ; of the outer toe, 

 10.25 inches; of the heel, 10 inches; of the foot, 23 to 25 inches; 

 of the step, 40 to 72 inches ; of the middle toe beyond the lateral 



