240 AN ATTEMPT TO DESCRIBE THE ANIMALS THAT MADE 



the middle, 1.5 inch; of the outer, 1.1 inch ; of the hind, 0.6 inch; 

 of the heel, 1 .2 inch ; of the foot, 2.6 inches ; of the step, 2.5 to 

 3.5 inches ; of the middle front toe beyond the rest, 0.6 inch. 

 Greatest width of the heel, near its posterior part, 0.45 inch ; near 

 the roots of the toes, 0.2 inch ; between the tips of the lateral 

 forward toes, 1 .5 inch ; between the inner and middle, 1 inch ; 

 between the middle and outer, 1.1 inch. Axis of the foot nearly 

 parallel to the line of direction. Distance of the axis of the foot 

 from that line, 1.4 inch. 



Fore feet. — Much smaller than the hind feet ; but only a few 

 of the toes can be seen upon the specimens yet found of the tracks, 

 — certainly not more than three. Enough, however, is seen to show 

 the quadrupedal character of the animal. On Plate 22, fig. 9, cop- 

 ied from a slab in Mr. Marsh's cabinet, and reduced three times, 

 we see the hind feet arranged in two nearly parallel rows, with 

 traces of a few of the fore feet in such a position as we should ex- 

 pect in the tracks of a quadruped. The hind foot, of the natural 

 size, with a part of the fore foot, is shown on Plate 15, fig. 8. 



Locality. — Turner's Falls, on the Gill shore, below the Falls ; 

 on very soft gray micaceous sandstone. 



Remarks. — Excluding the heel, the hind foot of this animal cor- 

 responds almost exactly to the Ornithopiis gallinaceus, though 

 smaller. But the heel and its quadrupedal character make it very 

 distinct. Yet if the Ornithopus Adamsanus shall be found to be a 

 quadruped, it will form a gigantic species of this genus ; and per- 

 haps it ought to be placed here now, since we have no evidence 

 that it is not a quadruped, and its large heel certainly makes it 

 probable that it is. The tracks of this species, and also those of 

 the Macropterna divaricans and Harpedactylus gracilis, were very 

 recently discovered by Mr. D. Marsh, a little below Turner's Falls, 



