go6 General Notes. [ November, 
strong home affection. 5th. That they usually pursue definite 
routes, and are guided in part by prominent landmarks, or by 
memory, and in part by “instinct” or inherited experience. 6th. 
That erratic movements are the result of transportation by storms. 
7th. That birds discern approaching meteorological changes. 
Tue Craw on THE INDeEx Dicit oF THE CATHARTID.—Birds 
form such an eminently distinct group in the present age—one so 
thoroughly isolated from any of the other natural divisions, that 
the discovery of any new factor in their anatomy, belong to what 
system it may, that tends to bring them nearer, by structural 
affinities, to one or the other of the great classes in nature, must 
always be regarded with peculiar interest by comparative anato- 
mists. A prominent example, of this, familiar to all of us, pre- 
sents itself in the discussions and special attention that the re- 
mains of Archeopteryx macrura has always received from such of 
"us as are interested in special homologies, and by naturalists gen- 
erally. 
The writer has been recently engaged in collecting together, 
from various sources, material from which he hopes, at no distant 
day, to produce a monograph upon the osteology of the Cathar- 
tide. Not long ago a skeleton of Catharista atrata was obtained, 
through the kindness of Mr. Robert Ridgway, from a friend in 
Florida—after it had been received at the Smithsonian Institu- 
tion. Mr. Ridgway and myself were examining it together, dis- 
cussing in a casual way some of the bird’s osteological bearings, 
and features, when my ornithological friend called my attention 
to an appendage at the extremity of the index digit—an addition 
to this vulture’s skeleton, that was at once recognized as a deli- 
cate and freely articulated c/aw. Our surprise was mutual, and 
an examination of the many specimens of vulturine birds, skins 
and skeletons, that the Museum afforded, and which were within 
our easy reach, was at once inaugurated. The results of this and 
overs, 
* pur 
attached to the manus below the carpal joint, usually, I believe, 
on the metacarpal bone. This is also the case in Parra Ugice 
and Palamedea, and others, but in these birds, as I have ie ‘ 
Stated, it is essentially an immovable spur, the counterpart of 
Same appendage as found on the posterior aspect of the ee 
_ Metatarsus in the common barn-yard fowl and game cock as 
_ asin these birds, often used as a weapon of attack during the — 
breeding season. | ne 
