322 ANATIDiE. 



portion of the curve, which they follow, ultimately dividing 

 into two slips, one of which — inserted upon the surface of the 

 bone of divarication — governs the length of the preceding 

 flexible portion of the tube ; the other slip passes off down- 

 wards to be attached to the inner surface of the breast-bone, 

 anterior to the first rib. The course of the muscle on one 

 side may be traced in the first anatomical figure. 



Dissection, which conclusively proved the distinction 

 between the Whooper and Bewick's Swan, has also shown 

 that the two Wild Swans of North America differ internally 

 as well as externally from the two Old World species already 

 described. The largest of the North American Swans, 

 superior in size to our W hooper, is called Cygrais buccinator, 

 or the Hunter's Swan, by Kichardson, in his ' Fauna Boreali- 

 Americana,' where the measurements and other particulars 

 of its history will be found. The Author was indebted to 

 the liberality of Richardson for a preparation of the very 

 singular organs of voice and the sternum of this species, 

 which will be found described and figured in the Transac- 

 tions of the Linnean Society', vol. xvii. An immature Swan, 

 which in the opinion of some ornithologists belongs to this 

 species, is in the Aldeburgh Museum ; being one of four 

 killed in October 1866 (Hele's ' Notes about Aldeburgh,' 

 p. 147). However, the sternum of another bird out of this 

 flock, proved, on examination, to have no cavity for the 

 windpipe, therein resembling the Mute Swan ; whereas the 

 genuine C. buccinator has a cavity like that in the Whooper ! 



The second species of North American Swan was described 

 by Dr. Sharpless (American Jour. Sc. xxii. p. 83), under 

 the name of Cijgnus americanus [C. columbianus, Ord] ; and 

 subsequently by Audubon . The Author was presented by these 

 gentlemen with the organ of voice and the sternum from 

 several examples of this species, which in some respects, inter- 

 nally as well as externally, resembles our Bewick's Swan, 

 although attaining a size and weight almost equal to those of 

 our Whooper ; the whole length reaching four feet six inches, 

 and the weight twenty-one pounds. Macgillivray was under 



