PHYLOGENT OF THE PAL.EOGNATHzE AND NEOGNATH.E. 



263 



validity of my conclusions rather than liis, for those who know his monographs on the 

 development of 4.f.ry^. and the skull of the mnornithid<B will a^n-ee that they are 

 monuments which mark an epoch in the history of this subject. In his work on the 

 skull of the Linornithidce he wrote : " The n,arked differences between the Moas and 



Kiwis are certainly for the niost part adaptive The real affinities underlyin<. 



these differences are, however, shown by the striking similaritv of the bones of the 

 palate in the two forms." 



The skull of CasHarius, it mny be remarked here, differs in no essential respect from 

 ih^ioi lJro,n<,us. In whatsoever it differs from Dromceus point to specialization, as, 

 tor instance, the development of the casque upon the mesethmoid (p. 199, PI. XLIV. 

 fig. 3) and the small quadrato-jugal fossa. 



The skull oiLromceus, it would seem, must be regarded as the most generalized of 

 living birds, at least in so far as the bones of the palate are concerned. 



Strnthio somewhat nearly approaches Dromwus in the arrangement of these bones 

 Mhea, the 'Iinamous, the Linornithidce, and probably the ^pyornithidce agree more 

 closely one with another than with Dromxeus. 



Ai>teryx- differs from all in the direction of increased complexity of these part. 



We have now Struthio and Lronicens witli Casuarius opposed to Rhen, Linornithidce 

 and Cryptur,, and possibly ^pyornis. These last we may further subdivide by 

 means of the pelvis. This will separate Rhecc from the remaining forms; inasmuch 

 as m Bhea the pelvis is long and narrow, with the post-acetabular ilia meeting in the 

 middle line, as in Apteryx. 



In the Binornithidw, ^:Epyorni.s, and the Tinamous the post-acetabular ilia are 

 separated by the long transverse processes of the synsacrum. 



It may seem that this character of the pelvis is a somewhat artificial one, but 

 reflection will show, I tliink, that it is probably not so. It does not seem to belong 

 to the category of adaptive characters, since Rhea and Apteryx in the general confoi-- 

 mation of the pelvis agree, though their habits are very different, and both bear some 

 similarity to that of /y/r/^^/^/o— similar in so far as the great length and transverse 

 width are concerned. In the Tinnmidw, Linornithidce, and ^pyornis the pelvis owes 

 its great breadth to (1) elongated transverse processes, and (2) the broad dorsal plane 

 of the post-acetabular ilium. 



The pelvis of Struthio bears an undoubted resemblance to the Linornithine form, 

 inasmucli as, like Linornis or ^pyorni.% the transverse processes bear the pos(- 

 acetabular ilia away from all contact with the neural spines of the synsacrum. 



Fiirbringer's view with regard to the Lronueidce is not exactly in harmony with 

 tlie views adopted here, but if lends some support thereto nevertheless. He says 



Lromceus and Casuarius "bilden zwei sehr uahe verwandte Familien welche 



etwas holier als die Struthionidce, aber tiefer als die Rheidce stehen und im Ubrigen 



sowohl von den anderen Ratiten als von den Carinatcn eine entfernte 



2o 2 



