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that the animals that impressed them actually possessed the highly 

 developed respiratory organization of a bird of flight. One could hardly 

 venture, indeed, to reconstruct in imagination the stupendous bird which, 

 on Dr. Hitchcock's hypothesis, must have left the impressions called Orni- 

 thkhnites giganteus ; for before 1841, the only described relic of the ex- 

 tinct New Zealand bird did not warrant the supposition of a species larger 

 than the Ostrich. 



The species of Dinornis (Din. slruthoides) , in fact, to which that relic 

 belonged, we now know not to have exceeded seven feet in height, which 

 is the average stature of the Ostrich. But the bones of the Dinornis gi- 

 ganteus subsequently acquired demonstrate the existence, at a compara- 

 tively recent period, of a bird whose tridactyle foot-prints surpassed the 

 Ornithichnites giganteus of Prof. Hitchcock. 



The length of this foot-print to the extremity of the impression of the 

 claw of the middle toe is sixteen inches ; the breadth of the back part of 

 the impression is four inches six lines. The toes were broad and thick, 

 and we may plainly discern that the bird supported itself, like the Ostrich, 

 upon the under surface of the toes, from their extremities to the cushion 

 beneath the distal end of the proximal phalanges ; and that in making 

 the impression, the foot did not quite sink as far as the end of the meta- 

 tarsal bone. 



The length of a corresponding impression of the foot of the Ostrich is 

 eight inches ; the breadth of the posterior part of the impression three 

 inches ; the breadth of the distal end of the tarso-metatarsal bone two 

 inches and a half. According to these proportions, the breadth of the 

 distal end of the tarsometatarsal bone of the tridactyle bird that im- 

 pressed the Ornithichnites giganteus must have been three inches nine 

 lines ; but the breadth of the distal end of the tarso-metatarsus of the 

 Dinornis giganteus is five inches. According, therefore, to the propor- 

 tions of the Ornithichnites giganteus, the breadth of the hind part of the 

 foot-print of the Dinornis giganteus must have been six inches, and its 

 length twenty-one inches and a half. 



The genus Dinornis was characterized by a relatively broader foot than 

 the Ostrich, as we know by the tarso-metatarsal bones ; and this bone in 



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