428 Proceedings. 
we have never found any scapulo-coracoids of a different form from those 
articulating with the five species of Dinornis, and, as we have obtained a 
number of the most minute bones of the smallest species, it would be difficult 
to conceive that a bone of such considerable size should altogether have 
escaped, the more so as so many specimens of Palapteryx were excavated. 
And, although this is only negative evidence, it is so strong that there is not 
the least doubt in my mind of the non-existence of a bony scapulo-coracoid. 
The same might, indeed, have existed in a cartilaginous form, attached to the 
sternum by cartilage, but of this we have no evidence. Iam wellaware that 
on physiological grounds the presence of that bone seems to be indispensable 
for the mechanism of respiration in birds, as Professor Owen has shown from 
his dissection of Apteryx, and he has lately again called my attention to the 
fact (letter to me, dated British Museum, August 5, 1873) ; but, with the 
data at present before us, I cannot alter my views, the more so as I do not 
deny that such a process might have existed as cartilage. 
It will be seen from the subdivisions given above that I have not used the 
term Dinornis giganteus, as there seems to be a specific difference between the 
species of that name from the northern island, to which that term was first 
given by Professor Owen, and tbe largest bird of this island. In this I have 
followed Professor Owen, who has proposed the specific term of Dinornis 
maximus for the latter, which appears to have been altogether of more gigantic 
proportions than the North Island bird. I was once under the impression 
that a specific difference could be traced between the largest skeletons known, 
for which the above term maaimus was first used by Professor Owen, and the 
somewhat smaller skeletons, for which for some time the designation giganteus 
was retained by me ; but, after a careful examination of a number of skeletons, 
there remains not the least doubt in my mind that they all belong to the same 
species, with a gradual decrease of size and robustness. And even assuming 
that the largest skeletons belonged to the female birds—a similar considerable 
difference in size being also constant with the different species of Apterya— 
there are so many intermediate forms that even the supposed line of division 
between both sexes is exceedingly difficult to draw. 
Moreover, and this is peculiar to Dinornis maximus, there are scarcely two 
skeletons entirely alike; there are some which have a remarkably long 
metatarsus, whilst the other leg bones do not (at least at the same rate) 
increase in size; others are much stouter for their height. Altogether we 
might trace the same peculiarity in size and form as in a series of human 
skeletons selected at random. 
The same is the case with the skeletons of the immature birds of this 
species, of which we possess portions from the chick to the full-grown giant 
bird, where the tarsal epiphysis is not yet so closely united with the metatarsus 
