222 



OSTEOLOGY OF ANSERES. 



The extensive coraeoidal beds of the anterior border are separated 

 by a pit in the median line, and not a vestige of such a thing as the 

 manubrium is to be seen. 



From the pit just mentioned to the far-projecting cariual angle a 

 straight osseous welt is raised, above which the anterior margin is 

 convex and sharp. 



Fig. 3. Sternum of llergus serrator.- pectoral aspect: life size. By the author, from specimen 16626, 



Smithsonian collection. 



The keel itself is low and extends clear back to the hinder margin 

 of the bone proper; its inferior border is thickened and gently convex 

 throughout its extent. 



As a very good example of the appearance of the sternum among 

 the Ducks I present a drawing of the pectoral view of the bone chosen 

 troin the American Eider (& dresseri, Fig. 13). In this form the pro- 

 foundly two notched hinder portion is well shown, and here, too, we 

 observe that the anterior part of the keel does not project as in Mcrpus, 

 though it is not an uncommon thing to find it so even among true Ducks. 



