386 STERNA OF THE AGAMI. 



that is to the bones which give the entire structure its 

 form and its leading characters, we find that it is by 

 the sternum, and those attached bones the coracoids, 

 which are never wanting in a bird, be its habit what it 

 may, and never present in any other animal, that we 

 determine a bird to be a bird and nothing else. The 

 preceding figures represent the sternal apparatus of the 

 agami. 



Upon examining these representations, it mil be 

 found that the bird to which they have the greatest 

 resemblance is the gallinule ; that the general form 

 of the sternum is nearly the same ; but that as the 

 gallinule is a much more aquatic bird than the agami, 

 its sternum possesses two very elongated lateral pro- 

 cesses, while that of the agami is entire. The ribs 

 are also more numerous in the agami, and occupy 

 a greater portion of the length of the sternum, and 

 though the scapular is not so long, it is broader, has 

 a slight approximation in form to that of the penguin, 

 and is strongly articulated to the head of the coracoid, 

 while that bone, though well set as to the resisting of 

 cross-strains, is rather loose in its articulation with 

 the sternum as seen laterally. The furcal bone is 

 much more slender than in the gallinule, and it has a 

 process at the junction of its branches directed toward 

 the keel of the sternum as in the gallinidae, whereas 

 that of the gallinule has only a small tubercle on the 

 upper side at that point. The whole line of the furcal 

 bone of the gallinule, when viewed laterally, presents 

 an arch, though a flattened one, to the front ; while 

 mat of the agami, though slightly convex near the 

 articulation with the other bones at the shoulder, is 

 concave to the front in the part next the sternum. 

 Throughout its whole length, this bone is remarkably 

 slender and feeble as compared with the sternum, 



