CHAR A CTERISTICS. 



175 



While agreeing with the owls and the ospreys in their desmognathous palate, 

 their hooked beak and curved talons, and the presence of a cere, the Accipitrines 

 differ from both in that the fourth toe is not reversible ; while they resemble the 

 latter and differ from the former in their laterally- 

 directed eyes, which are never surrounded by com- 

 plete discs, and their firm plumage. In the bones 

 of the leg the tibia differs from that of the owls 

 in possessing a complete bony bridge at the 

 lower end, while in the typical forms this lower 

 end is remarkably flattened from back to front. 

 The cannon-bone, or metatarsus, as shown in the 

 accompanying figure, is also longer than in the owls 

 and ospreys, and lacks the bridge at the upper end 

 found almost universally in these groups; while at 

 its lower end the three trochleae, instead of forming 

 a very high arch when seen from below (compare 

 the figure on p. 140), are situated nearly in the same 

 transverse plane. Hence the metatarsus at once 

 serves to distinguish an owl or an osprey from an 

 Accipitrine. In addition to its bridged palate, the 

 skull of an Accipitrine agrees with that of an 

 owl in the absence of any production of the lower 

 mandible beyond its point of articulation with the 

 {quadrate bone, but it differs by its more elongated 

 form. Like those of the owls, the young have a 

 downy coat, but the eggs, although occasionally 

 white, are very generally more or less coloured, 

 usually with reddish blotches on a pale ground. 

 The whole group is carnivorous, like the owls and 

 ospreys ; but, while some of its members kill their 

 own prey, others live on carrion. The Accipitrines 



may be divided into four distinct families, namely, processes of upper end ; a.h, points of 

 the falcon group {FoZconidce), the vultures {Vul- SceTS'firtuoe.'^'''*'"^' ^°''°''''' ^'' 

 turidce), secretary - vultures (Serpentariidce), and 



American vultures (Cathartidce). The two first of these families are closely 

 allied ; the other two differ greatly both from the first two and from one another. 



THE LEFT CANNON - BONE OR META- 

 TARSUS OF THE BUZZARD. 



From the upper (A), front (B), lower 

 (C), and hinder (D) aspects, c.d, hinder 



The Hawk Tribe. 



Family FalconiDu^. 



The present family, which includes the falcons, hawks, kites, buzzards, eagles, 

 etc., constitutes together with that of the vultures the typical Accipitrines, which 

 are collectively characterised by the following features. In the head the nostrils 

 are separated by a median partition, while on the base of the skull there are no 

 basipterygoid processes. The feathers have well-developed aftershafts, and the 



