EXTINCT SPECIES. 147 



no place for doubt as to the previous existence of a giant 

 bird, to which the traces are referable. Naturalists were 

 slow to come to this conclusion, so extraordinary did it seem 

 for a bird to have lived at a period so remote as that when 

 these geological formations were deposited. To gain some 

 idea of the antiquity of that formation, one has only to re- 

 member that the conchylian stage is only the fifth in the 

 order of time of the twenty-eight stages of which, according 

 to Alcide d'Orbigny, the crust of the earth is made up, from 

 the period of primitive rocks to the present date. However, 

 many recent facts have tended to prove that several animals 

 mammalians and saurians amongst others are far more 

 ancient than had been imagined ; under the light of which 

 evidence these giant-bird footprints have lost much of the 

 improbability that once seemed to attach to them. 



Pass we on now to the traces of another very curious 

 bird, the existence of which has been demonstrated by Pro- 

 fessor Owen, according to whom the creature must have 

 lived at the epoch of the schists of Sobenhofen. The name 

 given by Professor Owen to this curious extinct bird is 

 Archeopterix. Its peculiarities are so numerous that for some 

 time naturalists doubted whether it should be considered a 

 reptile or a bird; between which two there exist numerous 

 points of similarity. And now, whilst dealing with bird- 

 giants, it would be wrong not to make some reference to a 

 discovery made in 1855, at Bas Meudon, of certain osseous 

 remains, referable to a bird that must have attained the di- 

 mensions of a horse; a bird that floated on water like a 

 swan, and poised itself at roost upon one leg. Monsieur 

 Constant Prevost, the naturalist who has most studied this 

 bird, gave to it the name of Gastornis Parisiensis. The bony 

 remains of this creature were found in the tertiary forma- 

 tion in a conglomerate associated with chalk ; circumstances 

 which refer the gastornis to a date more remote than any 

 yet accorded to any other bird. 



