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 considei'able 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. I am well aware 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 the lai'gest bii-d of this island. In this I have 

 followed Professor Owen, who has proposed the specific term of Dinornis 

 onaximus 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 maximus 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 Apteryx^ 

 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 ; thei-e 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 fi-om the chick to the full-grown giant 

 bird,, where the tarsal epiphysis is not yet so closely united with the metatarsus 



