PHYLOGENETIC 49 



that the extinct Ichthyornis and Odontopteryx belong. The 

 first-named, as we have already remarked (p. 37), was a bird of 

 powerful flight, whose jaws were provided with a formidable 

 armature of teeth, while of the Odontopteryx of the London 

 Clay but little is known, save that the jaws were deeply serrated 

 by a series of bony outgrowths of the edges of the jaw which 

 were encased in horn. 



According to some authorities the Accipitres are descended 

 not from- the Ciconiiformes but from a Gruiform stock, of 

 which more presently. On the whole, however, the evidence 

 seems to support the origin here indicated. The strange Sec- 

 retary-bird {Serpentarius) on the one hand, and the Cathartse 

 or New World Vultures on the other, represent the most aber- - 

 rant and puzzling of the group, and both have preserved many 

 proofs of their primitive character. Of the more strictly, or 

 more specialised, Accipitrine types we have three more or 

 less distinct groups — the typical Eagles, Buzzards, Kites and 

 Hawks; the Vultures; and the Falcons; the last being the 

 most highly specialised of all. 



The Cathartse or New World Vultures probably represent 

 a distinct branch, running parallel with the rest of the Accipi- 

 tres, and descended from the same stock. 



The origin of the Anseres, as we have already remarked, 

 is not difficult to trace ; inasmuch as they are probably de- 

 scendants, if not of the archaic Screamers — Palamedea and 

 Chauna — at least of the stock from which these arose. That is 

 to say, the Screamers may either be regarded as the living re- 

 presentatives of the actual ancestors of the Anseres, more or 

 less modified by time, or as an offshoot of these ancestors retain- 

 ing most of the original characters thereof 



In two important characters the Screamers differ from the 

 Anseres however. In the first place they lack the peculiar 

 fleshy, horn-fringed tongue and the lamellae along the edges of 

 the beak, so characteristic of the Anseres ; and in the second 

 they have an extremely emphysematous skin, a character met 

 with again, it is to be noted, among the Steganopodes. As to 

 absence of the horny lamellae of the beak and tongue. This is 

 really not very important. Incipient kmellse may well have 

 been present in the earlier generations and have become 

 eliminated later, while in the true Anseres they gradually 

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