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largest tibia, belonging to the Din. giganteus, presented the extra- 
ordinary dimensions of two feet eleven inches. The shaft of a 
smaller tibia, about two feet long when entire, was referred to the 
Din. struthoides, and there were four entire tibie of the Din. didi- 
formis. In the series of femora, after the description of the generic 
characters of the bone, the specimens were pointed out which be- 
longed to the Dinornithes giganteus, struthoides, didiformis, and oti- 
diformis, and two other entire femora were described and their di- 
stinctive characters shown, which indicated, unequivocally in the 
author’s opinion, a fifth species of Dinornis, of the size of the Emeu, 
and which was, therefore, named Din. dromeoides. 
Three pelves, more or less perfect, and portions of two others, 
were described, and were referred to the Din. giganteus, dromeoides, 
and didiformis. Three cervical and two dorsal vertebree also indi- 
cated three distinct species of Dinornis, and all of them presented 
the common character of unusual strength of the spinous and trans- 
verse processes. Comparative dimensions of most of the bones ex- 
hibited were given. No part of the skull, sternum, ribs or wing- 
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 struthoides was seven feet high, which is the average 
stature of the Struthio Camelus. 
The length of the tibia and metatarsus of the Din. dromeoides 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 
