174 DEANE ON THE SANDSTONE FOSSILS OF CONNECTICUT RIVER. 
Descending in the scale of organization, this rock has retained the foot-print of in¬ 
sects and Crustacea with surprizing fidelity. Nothing in the strange history of the 
sandstone fossils, is more astonishing than the unrivalled perfection of the vestiges of 
these frail creatures. 
In this brief memoir I shall endeavor to portray some of these interesting hiero¬ 
glyphics of extinct existences. Fig. c, pi. 18, is an unimpeachable footprint of a bird, no 
other animal could impress it. Its analogies are unmistakeable. It is a left foot, the 
inner toe has two, the middle three, and outer four j>halanges, exclusive of the nail, 
which is in exact correspondence with the feet of existing trydactylous birds. The 
triple-lieaded, or distal extremity of the tarso-metatarsal bone, is also unequivocally 
impressed. Naturalists may, if they prefer it, explain the origin of these impressions 
upon the hypothetical existence of such monsters as biped reptiles, but by the unerring 
laws of comparison, I have never hesitated for a moment to ascribe these footprints 
to birds. In this opinion I am sustained by a distinguished comparative anatomist, 
who, in relation to fig. c, remarks, “ that some naturalists would call it reptilian, be¬ 
cause, according to their idea of cosgomony, birds did not exist in the new red sand¬ 
stone period, and there are some very distinguished naturalists who maintain this 
doctrine, but I call it the footprint of a bird, cosmogony or no cosmogony.” 
Fig. a. is quadrupedal, andisBatrachian. Each foot has four toes radiating forward, 
and the anterior foot is considerably more advanced than is usual. This is a very 
beautiful specimen of these delicate footprints. 
Fig. cl has four toes, two diverging outward and two inward. They are thick and 
somewhat massive, and blunt at their extremity. Both the anterior and posterior 
feet are analogous as to form. 
Fig. e is an elegant and interesting example of the quadrupedal impressions, and 
the most diminutive ever seen. It is very perfect, yet it is difficult to comprehend 
the place to which the amimal who made them should be assigned. All the other 
quadrupeds move by alternate steps, but in this example both right and left feet fall 
simultaneously. There is no impression of a fore foot, but this is a common defect 
in delicate quadrupedal impressions, the impression of the fore foot not always being 
retained. It may be that the imprint of the anterior foot is obliterated by that of the 
posterior foot. The dragging of the foot from one step to another is distinctly pre¬ 
served. There were probably four toes. The surface upon which the creature moved 
is smooth as if polished, and no other would retain the imprints with such extraordinary 
fidelity. 
Fig. b is probably Saurian. It is exceedingly perfect. It is a hind foot with five 
heavy toes, if the appendage upon the left be considered as a toe. It has a Chirotherian 
aspect, but as it is a solitary example, and is separated from the fore foot, its true 
relations cannot be exactly determined. The fine preservation of its massive heel and 
toes renders it a very beautiful example of foot prints. 
