120 



FALCONIDyE. 



thought, which is circular, broad, and strong, affording a 

 permanent support to the shoulders. 



By an extended examination of the different species of 

 Buzzards and Harriers, it will be found that the characters 

 described as necessary to produce rapid flight decline gra- 

 dually. The sternum decreases in size, the keel loses part 

 of its depth, the coracoid bones and furcula become more 

 slight ; while the form of the cranium, the loose ruffled 

 feathers of the neck, as well as the softer and more downy 

 texture of the plumage generally, indicate an approach to 

 the family next in succession. 



A representation of the sternum of an Owl will be in- 

 serted as a vignette to one of the species, to afford a com- 

 parative view of the size and structure of the same part in 

 the diurnal and nocturnal Birds of Prey. 



