616 STRUCTURE AND CLASSIFICATION OF BIRDS 



Bromaus ; the other is smaller and further back in the 

 substance of the coracoid. 



The sternum (fig. 246) is an exaggeration of that of 

 Drommus, being longer and more pointed posteriorly. Four 

 or five ribs articulate with it. 



The pelvis too, though very like that of the emu, is (fig. 

 247) an advance upon it in structure. There may be ((7. 



Fig. 246. — Sternum of Cassowaey (afiee Mivaet). 

 c, coracoid groove ; mx, posterior end. Other letters as in fig. 242. 



galeatus) or may not be an osseous union between pubis 

 and ischium and between ischium and ilium. 



The ostrich skull is rather unlike that of the other two. 



The vomer is very short ' and does extend back as far as 

 the articulation of the palatines and pterygoids. The latter 

 bones articulate not only with the basipterygoid "processes 

 but with the basisphenoid ; they bear off the palatines, which 



' ' W. Gbueee, ' Ueber das Thranenbein der straussartigen VOgel,' &c., Bull. 

 Ac. Sci. St.-Pitersb. 1855, p. 161. It varies somewhat in length according to 

 FiJEBKiNGEE, and was found in one case to be not unlilte the vomer of an 

 eegithognathous bird. 



