No. 482] OSTEOLOGY OF THE TUBINARES 



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more and more dubious as our knowledge of the structure of birds 

 increases — there is little in the character assigned to the groups 

 PelargomorphsB and Dysporomorphce by Professor Huxley that 

 is not applicable to the general Petrel type." (Zoc. cit. p. 434.) 



In this connection it is interesting to observe that the Tubinares 

 possess, in common with the Cathartidse, the Steganopodes, and 

 the CiconiidfE, a deep-keeled, broad and well-developed sternum ; 

 external osseous nares holorhinal; articular ends of mandible 

 posteriorly truncated; an evident tendency of the })a]atine bones 

 to unite with each other for their posterior moieties; powerfully 

 developed clavicles, which are strongly curved, — and these 

 osteological characters co-exist with other similarities to be found 

 in other parts of the morphological organizations of the respectix e 

 groups mentioned. 



Structurally, the Cathartidse are of great interest, and the 

 anatomy of those peculiar terrestrial scavengers must be still better 

 known to us than it is, before w^e can hope to trace their probable 

 ancestry. 



Remotely akin to the Steganopodes, the Falconida^, or more 

 generally, the Accipitres, also are linked with these more lowly 

 avian groups, — as are also the Ardeida\ through Scopus. 



During the ages past, it is quite evident tliat hosts of intermediate 

 forms linking these families and oioiips luivc perished and become 

 extinct. This, taken in connection with \\\v very marked speciali- 

 zation of the remaining genera, goes far towards proving the great 

 antiquity of the entire group, and how vast that extinction of the 

 less specialized forms must have been. 



My impression is that perhaps the Tubinares on the one hand 

 see their nearest relatives in the Steganopodes, in fact there can 

 now hardly be any doubt upon this point, — while upon the other 

 hand I am inclined to think that the penguins (Impennes) might 

 be with truth placed next below them, as Furbringer has done. 

 But such questions as these I will take up more thoroughly later 

 on, when I come, in another connection, to draw up my scheme 

 of classification for the Class Aves, and after I have paid further 

 attention to the osteology of other existing groups. 



Note: — In closing this Memoir I would say that since it was 

 written there has appeared in the American Naturalist my con- 



