PhilosopMcal Institute of Cant&rhury. 425 



refer to. Such a series would have affoi-ded him at a glance a confirmation 

 that the new arrangement which I venture to propose in the following notes 

 is not based altogether upon unsound principles. 



I am well aware that there are still many naturalists who think that the 

 division of the bones of our extinct avifauna into so many species is a mistake, 

 and that future i-esearches will prove that what appeared to Professor Owen as 

 several well-defined species were after all only various stages of age and growth 

 of one and the same kind. However, in this respect the collections of the 

 Canterbury Museum bear a strong confirmation of the correctness of the great 

 English anatomist's conclusions. We possess, not only young bones of each 

 species, from the chick to the full-grown bird, where — to take only one bone as a 

 guide — the tarsal epiphysis of the metatarsus is not yet quite anchylosed,* 

 but we have of each species a series of specimens of generally two distinct 

 sizes, from which we may conclude that they represent the male and female 

 bird of each species. In some instances, of which I shall speak more fully in 

 the sequel, we possess of each species four distinct sizes, which might represent 

 the two sexes of two distinct but closely allied species. 



Although Professor Owen thinks that the back toe {hallux) was only a 

 small functionless appendage to the foot, and that thus the existence or non- 

 existence of such bone is of no consequence, and has, therefore, felt obliged to 

 abandon this ground of generic distinction, I am more convinced than ever 

 that it is of great importance, and that the principal division of our extinct 

 struthious birds has to be based upon this, as I believe, constant chai-acter.t 

 If we add to this all the other distinctive features, which I shall enumerate in 

 the sequel, such as the existence or non-existence of a bony scapulo-coracoid, 

 the shape of the sternum and of the bill, and many others, the presence or 

 absence of a hallux becomes of still more importance. 



* We possess, amongst others, the leg bones of a specimen of Dinomis maximus, 

 which is in size only second to the largest bones we have, but in which this immature 

 character in the metatarsus is not yet quite effaced. 



+ I formerly believed that an impression observed on the back of one of the first 

 metatarsals of Dinomis ingens I ever obtained was there for the articulation of the back 

 trochlea, but since then several more specimens of that species have passed through my 

 hands, which showed that impression either only faintly or not at all. Dr. Jaeger, of 

 Vienna, articulated a small back trochlea with the skeleton of Dinomis ingens found in 

 the Moa Cave of Nelson, but there is no evidence that the small bone in question belonged 

 to it. In my first paper of measurements, on page 85 of the first volume of the 

 Transactions of the New Zealand Institute, I have already pointed to the distinct 

 rough groove which invariably exists at the back of the metatarsus of a number of species, 

 which I have now ventured to unite under the term PalajjterygidES. I may add that a 

 number of back trochlese in the possession of the Canterbury Museum, as to form and 

 size, agree in a remarkable degree with the form and size of the bones of the different 

 species belonging to that family. It would be strange if this striking coiucidencr, 

 together with the rough grooves previously alluded to, should have misled mc tu draw 

 wrong conclusions therefrom. 



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