Two New Species of Fossil Footmarks. 51 
15°. Length of the middle toe, 2 to 3 inches; do. of the inner 
toe, 15 to 2 inches; do. of the outer toe, 1:8 to 2°3 inches; do. 
of the inner toe, 0°65 to 08 inch; do. of the second and third, 
(supposed to make but one impression,) 0°6 to 0°8 inch; do. of 
the first of the middle toe, 0:64 to 0:8 inch; do. of the second 
phalanx, 0:53 to 0°8 inch; do. of third and fourth, 0-4 to 0°8 inch ; 
do. of the first of the outer toe, 0:4 to 0-54 inch; do. of the sec- 
ond, 0:3 to 0:4 inch; do. of the third, 0-26 to 0°35 inch; do. of 
the two last, 0-33 to 0-45 inch. Tracks in a right line, and the 
axis of the foot coincident with that line. 
Distinctive Characters.—The most striking characters by which 
the tracks of this animal are marked off from all others, are the 
hear approach to parallelism of the lateral toes, and the great 
length of the step compared with the size of the foot. This is 
particularly the fact in respect to the smaller of the outline tracks 
given on Fig. 2, a; for the animal by which this was made, h 
astride of two feet: nor is this confined to a single specimen ; 
so that the idea that the animal was running, is not probable, 
The great disparity between the step in the large specimen (fig. 
2, b) and the small one (fig. 2, a), has led me to suspect that in the 
above description I may have embraced two species: but their 
Gill, and the latter from South Hadley. I am more disposed to 
this opinion, from the fact, that I find another row of tracks on 
the same slab from South Hadley, that contains fig. 2, a, running 
in the opposite direction, and about as large as fig. 2, b, yet exhib- 
iting a stride of 29 inches. See the two rows on #18. 1, a, a, a, 
4, and b, b, b, b. ; gon 
The ratio between the length of the foot and the step in this 
Species, (taking the two examples on fig. 1 as our guide,) is 
Much greater than that of any other anu hose footmarks I 
have found. 'That ratio is 8 for the smaller track, and 8°3 for the 
er: that is, the step is eight times larger than the foot. Ap- 
plying the rule which I have suggested for ascertaining from 
these numbers the length of this bird’s leg,* we find it to be 39 
* See Final Report by the writer on the Geology of Massachusetts, vol. ii, p. 522. 
