40 THE AUSTRAL AVIAN RECORD [Vol. IV. 



of technical terms relative to the morphology, the majority 

 of which are httle understood even by the speciaUst, and 

 the comparative value of the ones utilised has never been 

 calculated. 



To diagnose groups by means of such variable items as the 

 muscle formula, the presence or absence of basi-pterygoid 

 processes, the oil gland and the nature of the syrinx implies 

 the absence of any " deep-seated " characters, at least of any 

 stabihty. It is not our intention to disparage morphological 

 items, but to assert that such are not yet sufficiently under- 

 stood to be relied upon for the differentiation of groups, except 

 in a confirmatory manner. The external features, especially 

 the growth stages, must be fully appraised, and in doubtful 

 cases reference made to anatomical features. 



As above noted, this is our first attempt at providing a work- 

 able classification of avine forms, and we hope that later we 

 may, utilising this as a basis, prepare a diagnostic complement, 

 as such is non-existent at the present time, and we have 

 been compelled to refer to much scattered (and contradictory) 

 literature, while little has been done in many directions. 



Class AVES 



Subclass Dromaeornithes 

 Order Struthiones 



Suborder Struthioniformes 



Family Struthionidse 

 Order Rhese 



Suborder Rheiformes 



Family Rheidse 

 Order Casuarii 



Suborder Casuariiformes 



Family Dromiceiidse 

 Casuariidge 



Subclass Impennes 

 Order Sphenisci 



Suborder Sphenisciformes 



Family Spheniscidse 

 Aptenodytidse 



