December, 1844.] 179 



existences. All this, doubtless, occurred, and probably in the order we 

 have mentioned ; since these animals sported in their native elements, basked 

 on the oozy shore of a river or an ocean, and left the vivid imprint of their 

 feet in its plastic mud. These are a few inferences from established data, 

 which give beauty to geology, interest to these foot marks, and which are 

 well calculated to impress the mind with sublime and stupendous concep- 

 tions. 



In another locality, about twelve miles distant, but in the same synclinal 

 axis, on a slab of fine grained micaceous sandstone, which was taken from a 

 quarry about fifty feet beneath the rock already described, I found beautiful 

 imprints of hind and fore feet of an animal which I have ventured to refer to 

 the class Mammalia, and order Marsupialia. The hind and fore feet 

 are obviously different. On the hind foot the toes are five ; on the fore foot 

 there are but four ; the plantar surface on the hind foot is long, narrow, and 

 terminates in a distinct heel ; the fifth toe, whose imprint is feint, stands out 

 almost at a right angle with the foot, and much resembles the human thumb. 

 Indeed, the whole track does not look unlike the imprint of the human hand. 

 The length of the foot is five and a half inches ; the extreme spread of the 

 toes five and three-quarter inches ; the interval between the toes is from one, 

 to one and a half inches; length of the toes three inches. The fourth toe on 

 the fore foot stands out obliquely, like the fifth toe on the hind foot; length 

 of toes two and a-quarter inches ; length of the foot four and a half inches ; 

 the extreme spread of the toes four and three-quarter inches ; the interval 

 between the toes from one to two inches ; the nails are quite distinct, At 

 the external side of all the tracks there is a protuberance, which resembles 

 the rudiment of another toe. The plantar surface is round and full, and 

 seems to indicate that the greatest weight of the animal was before ; at all 

 events, the fore feet seem to have sunk more deeply into the plastic mud on 

 which these animals sported in the pristine ages of the world. The tracks 

 were in relief. I found but one that was in has relief. The fore and hind 

 foot follow each other very closely, there being an interval of only about two 

 inches between them. The length of the step was about twenty inches.* 

 I have given the average size of these truly remarkable tracks, but a few 

 were discovered, though not very distinct, at least two or three inches larger. 

 The slab was large, and contained twelve or fourteen very vivid imprints, 

 together with many that were not so distinct. 



This discovery evidently conflicts with an hypothesis long since thrown 

 out, and still maintained by distinguished geologists, that the atmos- 



* The apparent shortness of the animal in proportion to the size, (for it 

 must have been large.) the sluggishness of its movements — which may be 

 inferred from the fact of the feet not tracking together, and the difference in 

 the number of toes on fore and hind foot — seem to indicate an alliance with 

 the Batrachia. 



