ACCIPITRES 473 



number, but fourteen occur in Neophron percnopterus and 

 Bhinogryphus calif ornianus. 



There are potoder-down patches in Elanus, Circus, and 

 Gypaetus. The pterylosts is described for a variety of types 

 by NiTZSCH. 



The ventral tract broadens out on the breast, where 

 it is even sometimes (Gyps fulvus) divided into an outer 

 and inner branch. The dorsal tract forks upon the 

 shoulders ; in Gypaetus barbatus each limb of the fork is 

 connected by a single rov? of. feathers with the long single 

 median posterior portion of the tract. 



In Pernis apivorus these latter ,slender forks are figured as 

 being much longer, and in Falco peregrinus they dilate into 

 four or five rows of feathers before uniting. In Falco 

 brachypterus there is the usual dorsal fork, but between its 

 extremities lies the beginning of the very broad posterior 

 part of the tract. In all these birds there are lateral neck 

 spaces. The lumbar tract is but little marked, or is entirely 

 deficient. A large amount of detail is given in Nitzsch's 

 account of this family, which is treated more fully than many 

 others. 



The tensor patagii hrevis is simple in all accipitrines, and 

 there is never a biceps slip. There is, however, a certain 

 amount of variation in the tendon. The simplest form of 

 the tendon is seen in 



Vultur monachus 

 „ auricularis 



Falco melanogenys 

 ,, subbuteo 



Gyps fulvus i ,, cBsalon 



Tinnunculus alaudarius 

 Microhierax ccerulescens 



Thrasaetus harpyia 



where it is a simple tendon- without branches, as in many 

 picarian birds. On the other hand in 



Buteo vulgaris i Spilornis bacha^ 

 Circus maurus „ cheela 



Gouldi Neophron percnopterus 



Helotarsus ecaudatus Milvago chima-chiyna 



