OSTEOLOGY OF BIRDS 253 



example, and citing Seebohm as his authority, he says for the 

 Anseres " sternum with only one shallow notch." 



This is very wide of the mark, for the " notching " is almost 

 invariably deep in American species, or, as in Glaucionetta, the 

 sternum is fenestrated posteriorly, once upon either side of the keel. 



In the various works of Sir Richard Owen, I have read what he 

 has given us upon the osteology of existing forms as well as ex- 

 tinct species of Anseres. To some extent the labors of this great 

 authority will be used in a comparative way in the present treatise. 

 Moreover, I shall incorporate an illustrated memoir I published in 

 the Proceedings of the United States National Museum in 1889, 

 entitled Observations upon the Osteology of the North American 

 Anseres, and use the same cuts to illustrate the group characters 

 herein set forth. 



In 1890 Prof. William Kitchen Parker F. R. S. published an 

 excellent memoir On the Morphology of the Duck and the Auk 

 Tribes, 1 but osteologically it will not assist us much here, as the 

 work deals most largely with the embryological stages of the forms 

 treated, and with demonstrating the difference between the Anatidae 

 and the Alcidae. 



In the Proceedings of the Zoological Society for 1875 Gar rod pub- 

 lished a good article On the Form of the Lower Larynx in Certain 

 Species of Ducks. Figures of these parts are given for S a r c i d i - 

 ornis melanonota( c J 1 et$),Rhodonessa caryophyl- 

 l'a c e a (J* et J), and Metopiana peposaca (J*). These 

 are all rare forms and do not occur in the United States avifauna. 

 Much work in the same direction is needed in the case of American 

 Anatidae. Eyton and also Yarrell left us something of value upon 

 the same subject; the former in his Anatidae, and the latter in his 

 British Birds. 



W '. A. Forbes touched upon the Anseres but very lightly. ' On 

 page 354 of his collected Scientific Papers there is an interesting 

 " Xote on Some Points in the Anatomy of an Australian Duck 

 (Biziura lobata)," which may some day be of assistance in 

 taxonomy. 



A most excellent contribution to the subject of the classification 

 of the Anseres is seen in Dr Stejneger's work upon the swans. 2 

 But five pages, however, are given to the osteological characters, 



1 Cunningham Memoirs, Roy. Irish Acad. Xo. 6, o pi. 



2 Stejneger, Leonard. Outlines of a Monograph of the Cygninae. U. S. Nat. Mus. 

 Proc. 1882. p. 174-221, fig. 1-16. 



