276 



The keel of the sternum has a slight bend towards the right side : this probably relates to 

 the habit of flying in circles, and to a tendency to describe the circle in one direction re- 

 quiring a greater force for the downward stroke of the wing on one side, and consequently a 

 greater space for the development of the pectoral muscles of that side. 



Mus. South. 



1430. The skeleton of the Carrier Pigeon (Columba cenas, var.). 



Of the 18 vertebroe between the skull and sacrum, the last five bear moveable ribs, of which 

 the four posterior pairs are united to the sternum by hsemapophyses. There is a sixth pair 

 of ribs attached to the sacrum, the hsemapophyses of which support rudiments of the same 

 elements of a seventh pair of ribs. The sternum presents the accidental variety of the bend- 

 ing of the keel to the right side, and the two median notches are converted into foramina. 



Purchased. 



1431. The skeleton of a Tumbler Pigeon (Columba oenas, var.). 



The atlas and dentata are wanting : of the other 1 6 vertebrae between the skull and 

 sacrum, the five posterior bear moveable ribs, of which the last four pairs are united to the 

 sternum by hsemapophyses : there is a sixth pair of ribs attached to the sacrum, the hsein- 

 apophyses of which join those of the last pair of dorsal ribs. The development of the bones 

 of the beak is arrested in this variety. The posterior notches of the sternum are shallower 

 than usual. The metatarsals do not attain their normal length. 



Hunter ian. 



1432. The skull of a Tumbler Pigeon. Purchased. 



1433. The skull and hyoid bone of the Cushat, or Ring-dove (Columba palumbus}. 



Hunterian. 



1434. The skull of Columba palumbus. Purchased. 



1435. The skull of the Rock-dove (Columba livid). Purchased. 



Order SCANSORES. 



Family Psittacida (Maccaws, Parrots, Cockatoos). 



Genus Macrocercus. 

 1436. The skeleton of the Blue and Yellow Maccaw (Macrocercus ararauna}. 



