38 
SYSTEM OF NATURE. 
occur in these deposits ; ” * thus calling the attention of 
his reader to the presence of the higher mammalious ani¬ 
mals, when even whales, the lowest on the scale, were not 
present. Again, the same author speaks of an opossum’s 
jaw found at Stonesfield, as “ one of the most precious 
relics of the past ages of the globe,— the only known ex¬ 
ample of mammalian remains in the secondary forma¬ 
tions .”f There is abundant proof of this co-existence of 
marsupials with the lower vertebrates. Speaking of oolite 
the same author remarks,—“ The land which then existed 
was peopled by reptiles and marsupial animals , and 
clothed with tree-ferns , palms and Cycadew^X Again, in 
reference to the hypothesis that this earth was in those 
days a half-finished planet, Mantell writes thus, — “ The 
proof that birds existed in the country of the Iguanodon, 
— that marsupial animals inhabited the region of the 
megalosaurus and pterodactyle , &c.”§ Dr. Buckland, 
in speaking of marsupials, observes, “ The discovery of 
animals of this kind, both in the secondary and tertiary 
formations, shows that the Marsupial Order, so far from 
being of more recent introduction than other orders of 
mammalia, is in reality the first and most ancient con¬ 
dition under which animals of this class appeared upon 
our planet ; as far as we know it was their only form 
during the secondary period ; it was co-existent with 
many other orders in the early parts of the tertiary period, 
&c.”|| Professor Owen, in a letter to Dr. Buckland, says, 
“ It is interesting to observe that the Marsupials, including 
* Wonders of Geology, ii. 397. f Id. ii. 395. J Id. ii. 408. 
§ Id. ii. 443. 
j| Buckland, Bridgw. Treat, i. 73 . 
