342 BEE-ZATEfi. 



processes formed laterally by the notches are not very 

 dissimilar in their situation to false ribs only inserted 

 on the sternum, and not on the spinal column. 



The other parts are equally well fitted for powerful 

 and long-continued flights. The coracoids are long 

 and strongly formed, -s^-ith their heads much enlarged ; 

 the furcal l3one is a perfect arch, placed, like that of 

 the falcons, in the position of greatest strength and 

 strongly united to the coracoids. The scapulars also 

 are large and sithe-shaped. The furcal bone is not 

 united to the anterior part of the sternum, though 

 there is a. bifurcated process there, neither has it any 

 tubercle or other indication of a junction of two 

 branches at the middle, but consists of one unbroken 

 curve of nearly uniform strength throughout. 



This sternum is very beautifully adapted to the 

 habits of its owner. It combines great flying power : 

 length for the support of a body habitually on the 

 wing, and flexibility in the posterior angles, by means 

 of which the bird can better thread its way among 

 obstacles. And the birds of this and the analogous 

 genera are all powerful and long-continued in their 

 flight, although none of them are lofty fliers. Feed- 

 ing chiefly upon winged insects, by the banks of 

 rivers or over other humid surfaces in warm chmates 

 where vegetation is luxuriant, they have to pursue 

 their prey among twigs and branches, the pendent 

 festoons of climbing plants, and the tall stems and 

 large leaves of aquatic ones, so that while they pursue 

 on a swift and smooth forward flight, it is also neces- 

 sary that they should be able to glide and turn in 

 all directions AAith the utmost freedom. This facility 

 in turning is very necessary to birds which feed upon 

 insects, many of which are themselves carnivorous, 

 and hawk for their prey in the bushes or on the 



