OF GALLINACEOUS BIRDS AND TINAMOUS. 161 



bird-types are perfected : and, hypothetically, the " Struthionidse " may be said to form 

 one of the ancestral groups. 



The group under consideration — the Megapods — have a sort of tincture or stain of 

 this grallatorial nature ; yet this time it is not pluvialine, but ralline. Structurally, 

 there is not much of this ; but, just as a few drops of crimson fluid suffice to make rosy 

 a goodly vessel of pure water, so a slight dash of the Rail in the Mound-makers has 

 wrought a wonderful amount of isomorphism with that group of birds of whose nature they 

 possess so little. I need only refer to what follows to make good my assertion that, except 

 in the head, the Ralline taint is slight ; but that the resemblance of the two groups — the 

 large Land Rails and the Megapods — is most striking is at once shown by the fact that, 

 looking upon them from without, the eyes of an Owen have not detected their distinctness. 

 Yet the Megapods are, in some respects, more typically Gallinaceous than the Curassows 

 and Guans, and to a superficial observer both the skull and the skeleton generally would 

 seem to differ very little from that of the Common Fowl. The differences, subtle and 

 delicate as they are, yet are nevertheless of great importance to the systematist. 



A first view of the Talegalla's skull would, however, easily beguile a hasty observer 

 into the belief that it was most intimately related to the Palapteryx and the Notornis^: 

 but much of this depends upon the great strength of the head and the great height of 

 the bill. Careful comparison shows that both the Notornis and the Palapteryx have 

 their nearest relatives in Brachypteryx australis, Tribonyx mortieri, and Ocydromus 

 australis. I have carefully studied the structure of these three species, and I shall 

 compare the Talegalla with them ; then, its relations to these three being determined, 

 they will also be known with regard to the extinct and subextinct Rails. 



The occipital region of the Talegalla is really almost exactly intermediate between 

 that of Gallus and Ocydromus ; it is more vertical and less rounded than in the Rail, 

 less vertical and more rounded than in the Fowl. The occipital condyle is less dimpled 

 than in the Fowl ; more so than in the Rail, where the pit on its surface is extremely 

 small. Just so as to size : it is less than that of the Fowl, larger than that of the Rail. 

 The tympanic cavity is more shallow than in the Fowl ; it is, however, deeper than in 

 Ocydromus. The os quadratum has its head bifid, but not so much so as in Ocydromus ; 

 yet the posterior head of this " incus " lies in the tympanic cavity: we have seen that 

 it is nearly obsolete in the Fowl. As to the upper surface of the head, there is a more 

 even general convexity than in the Fowl ; but there is none of the smoothness and 

 almost polish of this part such as we see in the Rail. Above the orbits Rail- characters 

 cease, and the great breadth of this part (so narrow in the Rail) is altogether far beyond 

 what occurs in the Fowl : it is more like what is seen in the Curassow and in the 

 Wood-Pigeon {Columba palumbus) , and still more in the Dodo. The lachrymal is in a 

 special condition, and there is no counterpart of this in the other groups — only a slight 

 approach to it in Dendrortyx. In front, at the edge of the "hinges," a trace of the 

 ' See Mantell's ' Fossils of the British Museum' (pp. 117-128, and figs. 28-31). 



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