ROOM I. 



FOOTPRINTS ON STONE. 



67 



three digits are produced by the distal extremity of the 

 metatarsul bone : the hemispherical and circular spots with 



b 



LIGN. 21. FOOTPRINT OP A TRIDACTYLE BIRD, AND IMPRESSIONS op RAIN- 

 DROPS, ON SANDSTONE. CONNECTICUT. 

 (Nat. size.) 



which the surface of the stone is sprinkled, are the effect of 

 rain, which must have fallen before the footprint was made. 



The following is Dr. Deane's account of the specimens 

 before us : 



" It is rare to find a stratum containing these foot-prints 

 exactly as they were impressed by the animals ; for they are 

 usually more or less distorted and obliterated by the soft 

 nature of the mud, the coarseness of the materials, and other 

 circumstances, which have partially defaced them ; so that 

 although the general form of the foot may be apparent, the 

 minute traces of its appendages are almost invariably lost. In 

 general, distinct evidence of the peculiar phalangeal structure 

 of the toes of birds is wanting, and each toe appears to be 

 formed of a single joint, without the terminal claw. But a 

 few specimens have been discovered in which the true charac- 



