20 THE WONDERS OF GEOLOGY. 



along with their petrified and half-digested food, and with their 

 coprolites. 



Marsupials. — If the reptiles formed the transition from the marine 

 animals upward, the marsupials, as they are called, were the link 

 between the ancient reptiles and terrestrial quadrupeds. The mar- 

 supials, of which the opossum is an example, receive their young 

 (which, when born, are still immature) into an exterior pouch or 

 abdominal sack, and there nourish them at their paps, until they 

 are fitted to go abroad, and to encounter the vicissitudes of their 

 peculiar modes of life. These are the only animals hitherto found 

 below the chalk which approximate to the proper terrestrial 

 character. Dr. Mantell has, however, found the bones of birds in 

 the Wealden beneath the chalk, and our own countrymen, Pro- 

 fessor Hitchcock and Dr. James Deane, have discovered numerous 

 tracks of bipeds, probably of birds, some of them of gigantic dimen- 

 sions, in the new red sandstone of the Connecticut river. 



Fossils of the Chalk and Tertiary. — The chalk then follows, with 

 its immense and varied marine treasures — fuci, corals, echinoderms, 

 mollusks, fish, reptiles, with drifted wood, &c. : and then the lower 

 tertiary, still marine : and next, the middle tertiary, where proper 

 and fully characterized terrestrial animals are first found in abun- 

 dance. Through the remaining beds of tertiary, both marine and 

 fresh-water, we find molluscous animals, fishes, reptiles, and 

 vegetables, verging towards, and many identical with, those of our 

 own times ; and occasionally we discover also terrestrial animals, 

 but mostly different from the modern ; until, at last, in the dilu- 

 vium and alluvium, and the most recent sedimentary and concre- 

 tionary formations, we discern animals and plants, still more and 

 more like those now living, and finally graduating into perfect 

 identity with existing races. 



No Fossil Remains of Man. — Man, and his works, appear only in 

 the last stages, associated with such beings as now exist, both in 

 the animal and vegetable world. The pages of our Author will 

 disclose the great variety and extraordinary forms, and, in many 

 cases, colossal dimensions, unrivalled at the present time, of some 

 of the ancient animals, the megatherium — the sivatherium — the 

 dinotherium — the mastodon — the elephant — the hippopotamus — the 

 rhinoceros — the cavern bear — the tiger, and many others. But in 

 consequence of the most recent discoveries of geology, we are 



