﻿214 ILLUSTRATIONS OF FOSSIL FOOTPRINTS 



Fig. 1 is the smallest example of ornithic footprints known. It is a left foot, and dis- 

 plays the marks of peculiar organization tolerably well. The toes are massive ; the inner 

 one showing two lobes distinctly, and the middle and outer ones their respective num- 

 ber, but indistinctly : the nails are also slightly impressed. The impression of the 

 tarsus or distal extremity of the tarso-metatarsal bone is perceptible, and, altogether, it is 

 the best example of this most diminutive species I have seen. The step is four inches. 

 This species is rare, and I have seen it at no other localities. 



Fig. 2 is a beautiful specimen of the left and right foot of a bird, probably no larger 

 than the preceding ; but the impression differs in this respect, that the toes are more 

 numerous and less massive. The phalangeal ranks are not very distinct ; but the gen- 

 eral features of the track are very striking. Specimens are rare ; I have only seen them 

 at a pla^e called the Race, at the uppermost locality of fossil footprints, four miles above 

 Turner's Falls. This example of footprints is strictly analogous to those of several fami- 

 lies of the existing order Passerineae. 



Fig. 6 is a fine footprint, and is very rare. It was discovered by Mr. Marsh,* an 

 enthusiastic and successful explorer of these relics, who by his sagacity and industry has 

 accumulated a magnificent collection of footprints. The impression is deep, and the pha- 

 langeal ranks are conspicuous. The heel is singular, being as deep as the toes, and form- 

 ed of two equal oval parts, each pointing obliquely outward. The first joint of the middle 

 toe is prolonged backward to an extent so unusual as to suggest the probability of distor- 

 tion. It may be remarked in this place, that the inner and outer toes in fossil examples 

 project backward to a like extent nearly ; but the outer or long one invariably a little 

 the most. It is well to bear this fact in mind ; for the outer toe, in good examples, Fig. 

 4, for instance, appears to project much farther backward than the inner one. This appar- 

 ent difference is caused by the impression of the bilobed tarsus, one division of which is 

 placed in continuation of the long toe, and the other falls between the first joints of the 

 lateral toes, by the embrace of which it is in many species much modified in form. Such, 

 however, does not happen in Fig. 3, for instance. Fig. 6 is so rare, that neither Mr. 

 Marsh nor myself have seen it in consecutive series ; but the length of the step was 

 probably four or five inches. The bird was comparatively heavy. It will be noticed that 

 the imprint of the nails is much distorted, which results from subsequent changes in the 

 soft material upon which the impression is made. 



Fig. 5 is drawn from a cast presented to me some years since by President Hitchcock, 

 as was also Fig. 1, by whom both species were discovered. It is a fine, deep, regu- 



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* Wherever the discovery is not directly accredited to others, it has invariably been made by myself. 



