Fossil Footmarks of Turner's Falls. 75 



Falls, although unfortunately it is the least prolific of all. By 

 glancing at the plate it will be seen that the essential characters 

 of the feet of living birds, are accurately demonstrated, and the 

 analogy is calculated to fill us with astonishment. How an im- 

 pression of a fleshy foot could have been made in yielding clay, 

 and to the minutest touch preserved through a period of time so 

 vast, seems without deep reflection to be incomprehensible; yet 

 these are living witnesses that not only prove the immutability 

 of the creative design, but reveal to us a faithful page in the his- 

 tory of the earth long, long antecedent to the creation of man. 



It is rare to find a stratum containing these footprints exactly 

 as they were made by the animal, without having suffered change. 

 They are usually more or less distorted or obliterated by the too 

 soft nature of the mud, the coarseness of the materials, and by 

 many other circumstances which we may easily see would deface 

 them, so that, although the general form of the foot may be appa- 

 rent, the minute traces of its appendages are almost invariably lost. 

 In general, except in thick-toed species, we cannot discover the 

 distinct evidences of phalangeal structure of the toes, each toe 

 appearing to be formed of a single joint, and seldom terminated by 

 a claw. But, a few specimens hitherto discovered at this locality, 

 completely developed the true characters of the foot, its ranks of 

 joints, its claws and integuments. So far as I have ever seen; 

 the faultless impressions are upon shales of the finest texture, 

 with a smooth glossy surface, such as would retain the beautiful 

 impressions of rain-drops. This kind of surface containing foot- 

 marks is exceedingly rare ; I have seen but few detached exam- 

 ples, until recently it has been my good fortune to recover a stra- 

 tum containing in all more than one hundred most beautiful im- 

 pressions of the feet of four or five varieties of birds, the entire 

 surface being also pitted by a shower of fossil rain-drops. By 

 reference to the plate, it will be perceived that the fragments of 

 this stratum are arranged in three distinct examples, correctly 

 delineated upon a scale of one inch to one foot. The slabs are 

 perfectly smooth on the inferior surface, and are about two inches 

 in thickness. 



In the examination of these splendid relics, the first impression 

 of the mind is astonishment at the perfect preservation of the im- 

 pressions, their wonderful fidelity to nature, and the harmony that 

 prevails among so many lines of footsteps occurring upon such nar- 



