756 GEOLOGICAL SURVEY OF THE TERRITORIES. 
case, that when the opportunity offers for an examination of a perfect 
skeleton of this bird, that the number of segments in the spinal column 
will be the same.as in Sarcorhamphus; we have been assisted in arriv- 
ing at this conclusion by a critical examination of the ribs we have, as 
weil as the sternum and sacrum, that come very near to S. gryphus. 
We have carefully counted the vertebre in the different species before 
us, and in order that the reader may have them for easy comparison, 
we present the various results in the form of a table, here subjoined, in 
which will be found other important and useful data. The number of 
sacral vertebrae must be accepted with a due amount of caution, as we 
all know it is quite difficult to decide on the number of segments de- 
voted to the “sacrum” in adult birds, after anchylosis has thoroughlv 
been accomplished. 
Table for the comparison of the vertebre. 
oO Chi tne qa 
Ui RS esi Us 
_ ort nD 
ge | aS'S | as 
: so evels cas! 
Species. i qa | 283 on 
g 2 = | Sa | BUTE ee 
“= a = rs) =o ca 
le a a ou Hom q 
(>) S tS) rm sy @, sg 
© iS) a ° = 2 = 
is) A wn 'S) A A 
PE COMPOTNIANUB Sac ods assis Seer ee steele cles eens lean ete erall eee eee ga ik (ear ase We os i RIT ON ee 
S. gryphus . 17 3 13 6 2 3 
G. papa...-.- 17 3 13 6 3 3 
CL Gura 2 -=-- a 15 4 13 5 2 2 
Cathanistaratinata men se eee eeee ee eeeeeee Ss 15 4 14 5 3 3 
Neophron percnopterus 15 4 15 6 2 2 
Micrastur brachypterus 14 5 13 7 3 1 
| 
The specimen of Micrastur shows an interesting phase on the part of 
the ‘“‘hemapophyses” of the pair of sacral ribs, for we observe the one 
on the left side articulates with the sternum by expanded extremity on 
a perfect facet as the other sternal ribs do, while on the right side the 
‘‘ hemapophysis” of the sacral rib does not reach the sternum, but on 
the other hand lies along the posterior border of the sternal rib next 
beyond, as it does in many other birds. This gives us in this bird six 
facets on the costal border of the sternum on the left side, and only five 
on the right. 
Then, in our skeleton of Neophron we find a pair of sternal ribs, the 
last pair, springing from perfect facets on the sternum, that do not meet 
corresponding sacral ribs coming from above, but are apparently held 
in their position mainly by the intercostal muscles and membranes. 
Such facts and instances as these must make us necessarily a little 
wary, When we have only parts of skeletons in our possession, from 
which we have to decide as to the number of vertebra or ribs in any 
‘particular instance. 
The Cathartide being large-boned birds generally, we find that this 
feature is extended to the segments of the spinal column. The vertebra 
are large, and all their various processes well marked and strong. 
In the cervical region or division of the column we find the vertebral 
canals as usual, passing from vertebra to vertebra, along on either side; 
in each segment the tube remains throughout more or less subcireular, 
and is closed in the ordinary manner by the parapophyses and pleura- 
pophyses of each vertebra. The protection afforded the vessels is mark- 
edly complete, for it is only in the atlas and axis that we discover slight 
