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NEW YORK STATE MUSEUM 



does not -project as in Mergus, though it is not an uncommon 

 thing to mid it so even among true ducks. 



Lophodytes cucullatus has a sternum of the same 

 general pattern as the bone I have just described for Mergus. 

 Posteriorly, however, it is proportionately more flaring or wider, 

 while the keel is carried back farther, and the mid xiphoidal pro- 

 jection is not so strongly developed. At the forepart of the bone, 

 the carina is not nearly so far extended to the front as it is in Mer- 

 gus, and the coracoid processes are more acute. It is nonpneu- 

 matic as is the bone in other Merginae. In some respects the ster- 

 num of Lophodytes is more like the sternum of Clangula than 





Fig. 5 Left scapula and coracoid of M e r g u s s e r r a t o r , with furcula detached. 

 Natural size. Drawn by the author from specimen no. 16626, United States National 

 Museum Collection. (Compare figures 1—4) 



is the sternum of Mergus, particularly in the matter of the keel 

 not being so far produced in front. 



Shoulder girdle [fig. 5]. Most ducks, and I believe all the mer- 

 gansers, have a nonpneumatic pectoral arch. It is the case in our 

 present subject, and in a number of the former at my hand, as it 

 is also in Lophodytes. 



The furcula typifies the broad U-arch in Mergus, where the 

 curve is continuous and unchecked by the presence of a hypo- 

 cleidium. 



The bone is, as a whole, slightly curved backward, so each limb 

 presents a convexity to the front ; these become broader and later- 

 ally compressed as we pass in the direction of their free extremities. 



