PROFESSOR OWEN ON THE GENUS DTNORNIS. 267 



marked in the proximal phalanx of both the outer and inner of the three toes as in the 

 phalanx of the Dinornis. This phalanx measures one inch ten lines in length, one inch 

 two lines across the proximal end, and ten lines across the distal end : the articular 

 surface here is impressed by a vertical groove, as in the proximal phalanges of the outer 

 and inner toes in the Bustard, and it agrees in its general figure with that of the outer 

 toe of the left foot, but is much thicker in proportion to its length. The proximal 

 articulation matches in size with, but is not adapted by its configuration to, the outer 

 trochlea of the trifid metatarsal of the Dinornis didiformis. The foot-print of this spe- 

 cies was probably about the size of the Ornithichnites tuberosus of Prof. Hitchcock. 



From the foregoing comparison of the bones of the feet in the different species of 

 Dinornis with the impressions left by the ancient extinct birds of the American conti- 

 nent, it must not, however, be concluded that these were species of Dinornis. Agree- 

 ment in the size of the foot and number of the toes does not constitute specific or even 

 generic identity in Ornithology, as the living Emeu, Rhea and Cassowary testify ; and 

 though we may admit that the discovery of tridactyle terrestrial birds of a size more 

 gigantic even than that indicated by the Ornithichnites giganteus and Ornithichnites 

 ingens tends greatly to remove the scepticism with which such evidences of the extinct 

 animals of the Triassic period had been previously received, yet the recognized suc- 

 cession of varying vertebrated forms in the interval between that period and the present 

 forbids the supposition that the same species or genus of birds could have maintained 

 its existence throughout the several great changes which the earth's surface has under- 

 gone during that vast lapse of time. 



We see, in fact, how diversified are the few existing forms of Struthionidce -. almost 

 every species now represents a distinct genus. We know that this order has suffered 

 greater diminution within the time of man than any other in the class of Birds, perhaps 

 than any other in the whole animal kingdom. What, then, may not have been the 

 extent and variety of the wingless terrestrial birds in times anterior to man's dominion 

 over the earth ! 



Already the heretofore recorded number of the Slruthionidcs is doubled by the six 

 species of Dinornis determined or indicated in the foregoing pages ; and both the Maori 

 tradition of the destruction of the ' Moa'^ by their ancestors, and the history of the ex- 

 tirpation of the Dodo by the Dutch navigators in the Isles of Maurice and Rodriguez, 

 teach the inevitable lot of bulky birds unable to fly or swim, when exposed, by the di- 

 spersion of the human race, to the attacks of man. We may, therefore, reasonably 

 anticipate that other evidences await the researches of the naturalist, which will demon- 

 strate a further extent of the Struthious order of Birds anterior to the commencement 

 of the present active cause of their extinction. 



And since the texture of the bones of the former gigantic tridactyle Struthionida 

 of New Zealand proves that they resembled the Apteryx, in the comparatively low 



' The Maoris or Aborigines of New Zealand call the Dinornis ' Moa ' or • Movie.' 

 VOL. III. PART III. 2 N 



