498 STRUCTURE AND CLASSIFICATION OF BIRDS 



' Struthio has been found fossil in the Siwahk Hills, in South 

 Eussia and Samos. Bhea is found fossil in America (South). 

 Ltdekkee considers Hypselornis sivalensis, whose place of inter- 

 ment is indicated by the name, to be an emu. It is only known 

 from the second phalanx of the third digit of the pes. 



Genyornis Newtoni, from Australia,' with a skull a foot long, 

 seems to have been a gigantic emu. But it has not as yet been 

 fully described. 



Dasornis londinensis (from the Eocene clay of Sheppey) is 

 placed by Puebeinger among the Ratites, rather in deference to 

 the opinion of Sir E. Owen ^ than from conviction. Gadow, on 

 the other hand, places it among Stereornithes. It is only known 

 by a water-worn skull fragment, indicating a skull as large as that 

 of the DinornithidsB. It seems useless to speculate upon the 

 affinities of this fragment. 



Macrornis of Seeley must remain for the present a name. 



In surveying the muscular system of the Struthiones ' it is 

 clear that, so far as concerns the muscles of the manus, 

 Apteryx is, in accordance with other reductions in the bones 

 of that limb, the most degenerate type. On the other hand 

 (assuming, of course, the derivation of the Struthiones from 

 some carinate form) the shoulder girdle of Apteryx has 

 retained more of the primitive musculature than the other 

 genera. 



In all the genera the following muscles have disappeared : 

 the pectoralis propatagialis, biceps propatagialis, deltoides 

 propatagialis,* deltoides minor, scapulo-humeralis anterior, 

 expansor secundariorum.^ 



The pectoralis major is in all very reduced. 



All the struthious birds except Apteryx have also lost the 



VAN Bemmelen, ' Onderzoek van een Bhea-'Emhiyo,' Tijd. Ned. Dierk. Ver. 

 1888, p. ocv. 



' Stirling and Zietz, ' Preliminary Notes on Genyornis.'' &a., Tr. Boy. Soc. 

 S. Australia, xx. 



^ On Dinornis (part xiv.), Tr. Zool. Soc. vii. p. 145, pi. xvi. 



■• Gadow, Zur vergleichenden Anatomie der Muskulahtr des Bechens imd 

 der hinteren OliedmUsse der Batiten. Jena, 1880. 



' In Apteryx some elastic tissue in the patagium possibly represents this. 



' Traces have been asserted to exist in Apteryx and Dromceus, but require 

 confirmation. 



