50 PTERYLOGRAPHY. 



B. VULTURES OF THE NEW WORLD. 



The chief pterylographic character of these, as of the Old World Vultures, is to be found in 

 the formation of the pectoral portion of the inferior tract. This is not separated by a space from 

 the jugular portion, but the two sections of the tract are perfectly continuous. Just as the 

 inferior tract, gradually enlarging, has arrived over the pectoral muscles, it receives the axillary 

 tract, and thus acquires a very remarkable breadth. It then divides into two branches, which, 

 however, are generally weak, and are rendered indistinct by the circumstance that the feathers of 

 the tract are more scattered. The two branches are at first of equal width, and run parallel ; 

 towards the extremity of the great pectoral muscles they curve in towards each other ; and whilst 

 the inner one is continued unchanged as the ventral portion, the outer one is narrowed, and 

 returns by a narrow process, running along the margin of the musculus pectoralis major, to the 

 ventral part again. In this way the two branches enclose a pretty large insular space, the whole 

 tract thus presenting a very close resemblance to that of Centropus (Plate IV, fig. 18). This, how- 

 ever, does not conclude the list of the pterylographic peculiarities of the American Vultures ; but 

 we must add: 1. The amalgamation of the jugular part of the inferior tract with the cervical 

 portion of the spinal tract, which woiild convert the plumage of the lower part of the neck into a 

 continuous one, if the inferior space did not entirely or partially penetrate it. 2. The remarkable 

 narrowing of the dorsal portion of the spinal tract, which frequently consists only of two rows of 

 feathers, gradually diverging anteriorly, and connected with the branches of the fork of the cervical 

 part. 3. The presence of a large lumbar tract. 4. The constant and invariable presence of 

 twelve feathers in the tail. 5. The absence of a circlet of feathers at the apex of the oil-gland. 

 The broad, obtuse form of this organ seems to stand in relation to this. At its extremity there 

 are two distinct orifices. 6. The covering of the feet may also be cited as a characteristic element; 

 it consists of small scales upon the tarsus, but of scutes upon the whole of the toes : moreover, 

 besides the outer and middle toes, the middle and inner toes are united by a membrane. 



The elongated nostrils, paralled to the longitudinal axis of the beak, certainly remind one of 

 Neophron; but the absence of a bony septum between them is one of the most characteristic 

 external distinctions of the American Vultures : the tongue, moreover, has a series of teeth on its 

 margin, at least in C. papa and C. aura. 



I have examined C. yryphus, papa, aura and urubu (fcetens ILLIG.), and found in all some 

 little differences in the form of the tracts, but no characters from which I could justify their 

 division into the genera Sarcorrhamphus and Cathartes. 



4. CATHARTES. 



Down-feathers everywhere upon the spaces and between the contour-feathers ; the latter with 

 a few soft barbs in place of the deficient aftershaft. Head entirely or nearly naked, as also 

 the upper part of the neck ; the latter probably always. The pterylosis only commences at the 

 ruff of feathers, and is continuous, being only interrupted beneath by the inferior space ; the latter 



