XIII 



PHYLUM CHORDATA 



,383 



keel is vestigial or absent. The coracoid and scapula are com- 

 paratively small and completely ankylosed ; the acrocoracoid pro- 

 cess is vestigial, and the coraco-scapular angle approaches two right 

 angles. The wing is reduced in size and may be vestigial or absent. 

 There are large basi-pterygoid processes developed from the basi- 

 sphenoid. The vomer is large and broad. The quadrate articu- 

 lates with the skull by a single or partially divided facet. The 

 male has a penis. The young are precocious. 



FIG. 992. Apteryx australis, with egg. (From a specimen in the Royal College 



of Surgeons, London.) 



ORDER 1. MEGISTAXES. 



Including (a) the Emus (Dromceus) and Cassowaries (Casuarius\ 

 (b) the Kiwis (Apteryt., Fig. 992), and (c) the Moas (Dinornitltlda\ 

 Fig. 1007). 



ORDER 2. RHE.E. 

 Including the South American Ostriches (Rhea), 



