216 OSTEOLOGY OF ANSERES. 



Onion. J 11 fact, every advauce anatomy Las made in that direction 

 seems to have been attended by the one result, and that to assure us 

 of tlie soundness of the arrangement in question. 



Instead of this being a signal, however, for the anatomist to cast his 

 eves from this line of work and slacken the activity of his scalpel in 

 what he may think profitless employment, it all the more devolves upon 

 him to push his researches to a point nothing short of a perfect knowl- 

 edge of the structure of these forms. That we have not arrived at any 

 such state of perfection I could easily point out. As I have elsewhere 

 shown, even so profound an anatomist as Huxley, from lack of material 

 and established data, may occasionally fail to properly define an im- 

 portant characteristic, as he did in describing the sternum of these very 

 Ghenomorphce (P. Z. S., 1867). Again, it is but recently that Dr. Baur, 

 of XT ale College, claims to have discovered an additional joint in the last 

 digit or the middle linger of the embryo of the common Duck, a struct- 

 ure which is said to be visible at about the time of hatching. 



I have never had reason to change my opinion as to the value, 

 the incalculable value, of a complete knowledge of the morphology 

 of those living forms best known to us. With such a knowledge of 

 the structure of the anserine fowl we are far better prepared to push 

 our investigations, with infinitely greater chances of assured results 

 into the structure of allied groups than if we were not quite certain of 

 each and every detail in the organization of these known forms. 



The Anseres are well represented in the United States, and abundant 

 opportunity is afforded to study their structure. 



Further work is much needed in this line upon the air passages of the 

 entire group, the generative organs, and other special parts. 



The MergincB constitute the first subfamily under the Anatidcv, and 

 it has been awarded two genera in our fauna, viz, the genus Merganser 

 of Brisson, containing the Mergansers, and the genus Lophodytes of 

 Keicheubach, created to contain the Hooded Merganser [L. cucullatus). 



The Mergansers present us with some very interesting points in their 

 osteology, and the majority of these can be studied in the skeleton of 

 Mergus serrator, a very good specimen of which bird I have now at 

 band. I am indebted to the Smithsonian Institution for the loan of it 

 (Xo. 1GG2G of the Smithsonian Institution collection), and will now de- 

 scribe its skeleton. 



OBSERVATIONS UPON THE OSTEOLOGY OF MERGUS SERRATOR. 



Of the skull.— We find in this bird that the lamellae of the bill develop 

 tooth like serrations for the entire length of both mandibles. These 

 pseudo teeth, however, make no impression whatever upon the osseous 

 base of the bill, and in a well-prepared skeleton we would never suspect 

 their existence. Upon lateral view of this skull (Fig. 1) we see that the 

 superior mandible curves slightly upwards as we proceed toward its 



