FOSSIL MAMMALIA. V 



Fossil fish are found in the ancient marine strata as well as 

 in the more recent. So are the Crustacea which frequently 

 accompany them. There is reason to believe, that a sudden 

 revolution like that which a volcano might occasion, may have 

 overwhelmed such of them as are found in the greatest abun- 

 dance in certain places. The debris of osseous fishes are often 

 found : but of the cartilaginous we find nothing but the ver- 

 tebrae and teeth of squali. The coarse^ shelly limestone, as well 

 as the more recent strata, contains an immense quantity of 

 debris of the claws of Crustacea, and of the auricular bones of 

 different sorts of fish. 



The remains of terrestrial animals found in the fossil state 

 consist of bones, the antlers of certain species of cervus, and 

 teeth. It may be noticed, that such remains are rarely in a 

 state of petrifaction. The horns of other ruminants, hoofs, 

 claws, &c. are never found. 



Oviparous quadrupeds, such as the crocodiles of Honfleur, of 

 England, and the monitors of Thuringia, are found in very 

 ancient strata. The saurians and tortoises of Maestricht are 

 met with in the more recent chalk formation. The bones of 

 lamantins and phocae are found in a coarse, shelly limestone, 

 very analogous to that which covers the chalk formation near 

 Paris. The Baron has observed, in his great work, that up 

 to this point no remains of mammiferous land animals have 

 been found. Professor Buckland, however, to whose re- 

 searches fossil osteology is so much indebted, has, in the first 

 volume of the " Transactions of the Geological Society," 

 given an account of a mammiferous quadruped occurring in 

 an ancient secondary rock. In the calcareous slate of Stones- 

 field, in Oxfordshire, which lies in the upper part of the lowest 

 division of oolitic rocks, have been found, says the Doctor, 

 " two portions of the jaw of the didelphis, or opossum, being 

 of the size of a small kangaroo rat, and belonging to a family 

 which now exists chiefly in America, Southern Asia, and New 

 Holland.'*'' The Doctor refers this fossil to didelphis on the 



