734 GEOLOGICAL SURVEY OF THE TERRITORIES. 
these birds, the writer inserts the following valuable quotations from 
Nitzsch, an author who paid no little attention to the external charac- 
teristics of birds, more particularly the feather tracts. 
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 sepa- 
rated by a space from the jugular portion, but the two sections of the tract are per- 
fectly continuous. Just as the inferior tract, gradually enlarging, has arrived over 
the pectoral muscles, it receives the axillary tract, and thus acquires a very remark- 
able 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; to- 
wards 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 mus- 
culus pectoralis major to the ventral part again. 
In this way the two branches inclose a pretty large insular space, the whole tract 
thus presenting very close resemblance to that of Centropus (refers to plate). 
This, however, 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 would convert 
the plumage of the lower part of the neck into a continuous one, if the 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 of 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 tothis. 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 npstrils, parallel 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 leastin C. papa and C. aura. 
IT have examined C. gryphus, papa, aura, and uruber (fetens Ilig.), and found in all 
some little differences in the form of the tract, but no characters from which I could 
justify their division into the genera Sarcorrhamphus and Cathartes.—(Pteryl. Trans., 
from German Kd., by P. L. Sclater, Lond., 1867, p. 50.) 
From this point the author goes on to give, under ‘“Cathartes,” de- 
seriptions of the feather tracts of the birds that he mentions as having 
examined in the above list, in detail. 
The writer has to present to his reader the following material for ex- 
amination, of the skeletons of the Cathartide, upon which to base the 
results of his monograph. At the outstart we must deplore the fact 
that we do not possess the skeletons of the young of any of the family 
under consideration. To be sure, specimens of the young of Pseudo- 
gryphus have been obtained on several occasions, but at the present 
writing there are none in the Smithsonian Institution, and should such 
be obtained at a later date they can be discussed in some future paper. 
Of Sarcorhamphus gryphus we have in our study one very good skeleton, 
the property of the Smithsonian Institution, and kindly lent us for the 
purpose in hand; it however lacks the osseous part of the claw of the 
first digit of the hand. This is also the case in our skeleton of Gypar- 
chus papa, an unusually fine skeleton belonging to the Army Medical 
Museum, prepared by Prof. H. A. Ward, of Rochester, and obtained in 
Keuador, probably by some of his collectors. Of Pseudogryphus califor- 
nianus, also from the osteological cabinets of the Smithsonian Institution, 
we have two imperfect, skeletons; they, however, show the cranium and 
the majority of the principal bones. We may consider ourselves fortu- 
nate, however, in having even this much, for this Vulture is becoming 
rarer and rarer each year that slips by, a fact that is to be accounted for 
Sa” ie» 
