74 TERTIARY SERIES. 



Besides the many extinct species, and existing genera of 

 Mammalia that are enumerated in this list, the occurrence 

 of nine or ten extinct species of fossil Birds in the Eocene 

 period of the tertiary series, forms a striking phenomenon 

 in the history of organic remains.* 



In this small number of species, we have seven genera ; 

 and these afford examples of four, out of the six great 

 Orders into which the existing Class of Birds is divided, viz. 

 Accipitres, Gallinacece, Gralla?, and Palmipedes. Even the 

 eggs of aquatic birds have been preserved in the lacustrine 

 formations of Cournon, in Auvergne.f 



It appears that the animal kingdom was thus early esta- 

 blished, on the same general principles that now prevail ; 

 not only did the four present Classes of Vertebrata exist ; 

 and among Mammalia, the Orders Pachydermata, Carni- 

 vora, Rodentia, and Marsupialia ; but many of the genera 

 also, into which living families are distributed, were asso- 

 ciated together, in the same system of adaptations and rela- 

 tions, which they hold to each other in the actual creation. 

 The Pachydermata and Rodentia were kept in check by the 



♦ The only remains of Birds yet noticed in strata of the Secondary series 

 are the bones of some Wader, larger than a common Heron, found by Mr. 

 Mantell in the fresh-water formation of Tilgate Forest. The bones at 

 Stonesfield, once supposed to be derived from Birds, are now referred to 

 Pterodactyles. A discovery has recently been made in America by Pro- 

 fessor Hitchcock, of the footsteps of Birds in the New Red sandstone of the 

 valley of the Connecticut, which he refers to at least seven species, all appa- 

 rently Waders, having very long legs, and of various dimensions from the 

 size of a Snipe, to twice the size of an Ostrich. (See PI. 2Ga. 26b.) 



t In the same Eocene formation with these eggs, there occur also the re- 

 mains of two species of Anoplotherium, a Lophiodon, an Anthracrotherium, 

 a Hippopotamus, a ruminating animal, a Dog, a Martin, a Lagomys, a Rat, 

 one or two Tortoises, a Crocodile, a Serpent or Lizard, and three or four 

 species of Birds. These remains are dispersed singly, as if the animals 

 from which they were derived had decomposed slowly and at different in- 

 tervals, and thus fragments of their bodies had been lodged irregularly in 

 various parts of the bottom of the ancient laiic: these bones are sometimes 

 broken, but never rolled. 



