Professor Owen on the Dinornis. 379 



bones had been transmitted, but Prof. Owen proceeded to point out 

 the physiological grounds for concluding that the development of 

 the anterior extremities must have presented in the Dinornis an in- 

 termediate condition between that in the Emeu and that in the 

 Apteryx. 



The author then gave his calculations, from the analogies of 

 existing Struthious birds, of the height of the different species of 

 Dinornis. The largest, Din. giganteus, according to the proportions 

 of the Ostrich, must have stood ten feet five inches, but according 

 to those of the Cassowary, nine feet five inches ; its average stature 

 might be taken at ten feet. A diagram of the great extinct bird, 

 restored according to these proportions, was exhibited. 



The Dinornis struthioides was seven feet high, which is the average 

 stature of the Struthio Camelus. 



The length of the tibia and metatarsus of the Din. dromceoides not 

 yet being known, the height of five feet was assigned to it as a pro- 

 bable one ; its femur corresponds in size with that of the Emeu, 

 whose average measurement in captivity is between five and six feet. 



The height of the Din. didiformis was four feet; exceeding, there- 

 fore, the extinct Dodo (Didus ineptus), but evidently resembling it 

 in its stouter proportions and shorter metatarsus, as compared with 

 the other species of Dinornis. 



Prof. Owen next proceeded to consider the evidences of tridactyle 

 birds afforded by the impressions in the New Red Sandstone of Con- 

 necticut, called ' Ornithichnites,' and having pointed out the propor- 

 tions of the tarso-metatarsal bone in existing Struthious birds to 

 their foot-prints, indicated thereby the size of the same bone in dif- 

 ferent Ornithichnites, and reciprocally the sizes of the foot-prints of 

 the different Dinornithes, from those of their tarso-metatarsal bones. 



The two phalanges of the Dinornis, which were described and 

 compared in this section of the memoir, afforded pretty clear indi- 

 cations of the form and proportions of the toes in the two species 

 {giganteus and didiformis) to which they were referred. These data 

 showed that the trifid foot-print of the Dinornis giganteus must have 

 exceeded in size the Ornithichnites giganteus and O. ingens of Prof. 

 Hitchcock, and that the Din. didiformis must have left impressions 

 as large as those called Ornithichnites tuberosus. The author warned 

 his hearers against inferring identity of species or even genus between 

 the extinct Struthionidce of the alluvium of New Zealand and those 

 of the trias of North America, on account of correspondence of size 

 and number of toes, which the modern genera Casuarius, Rhea, &c. 

 proved to be insufficient grounds. He concluded by a comparative 

 review of recent and extinct Struthionidce, remarking on their peculiar 

 geographical distribution, on the conditions which favoured the for- 

 mer existence of so rich a development of the family in New Zealand, 

 and on the probable causes of their extermination. Evidence of the 

 recent character of the bones described was afforded by the great 

 proportion of animal matter which they retained, and the details of 

 the analysis of the earthy salts were promised for a future Meeting. 



