OSTEOLOGY OF BIRDS 



307 



geese), Plectropterus, Sarcidiornis, Chlanrydochen, and some others, 

 are commonly called geese. To the writer it seems almost certain 

 that they are allied to the sheldrake. The males of all appear 

 to have the curious enlargement at the junction of the bronchial 

 tubes and the trachea which is so characteristic of the ducks or 

 Anatinae and is wanting in the Anserinae or true geese. As much 

 may be said for the genus Nettapus." [Goose, p. 376] 



Elliott Coues has also observed that the " geese are directly con- 

 nected with ducks through the rather large sheldrake group, 

 the species of which resemble the latter in many external features, 

 but are more essentially like ducks. Characteristic examples of this 



Fig. 33 Skull of Branta canadensis hutchinsii; right lateral view. 

 Natural size. From a specimen in the author's collection, now in the New York State 

 Museum 



group are the European Tadorna cornuta and C a s a r c a 

 c a s a r c a ; there are several others in the southern hemisphere ; our 

 long legged arboricole genus Dendrocygna belongs in the imme- 

 diate vicinity, while the domesticated musk duck, Cairina mos- 

 c h a t a , is not far removed. Through such forms as these we are 

 brought directly among the ducks proper." [Key, 1903. p. 897] 

 There are a number of other authorities holding opinions similar 

 to those cited above. 



Skull. Judging from the skulls of Branta, Anser, and Chen, it 

 is evident at a glance that this part of the osseous system among 

 the geese is almost identically the same in structure and character 

 as the skull as found among the ordinary genera of ducks. For 

 example, there is no greater difference between the skulls of 

 Branta canadensis hutchinsii and Netta rufina, 



