760 GEOLOGICAL SURVEY OF THE TERRITORIES. 
the sacral vertebrze had better be taken up with the pelvic bones as an 
entirety and treated under the section devoted to the pelvis. 
In the South American Condor a complete arcade is formed by theneu- - 
rapophyses of the coccygeal vertebree, over the ultimate division of the 
myelon, and even the pygostyle is pierced for a short distance to allow 
the entrance of the nervous cord. ‘These bony arches are surmounted by 
knob-like tubercles throughout the series, that show a very feeble dis- 
position to become bifurcated at their summits. Many of the lateral 
elements of the vertebre are combined to form diapophysial processes, 
which, in this bird, are heavy and broad projections jutting from the 
centra on either side, bent downwards, and becoming wider and wider 
as we near the coccyx, to be suddenly suppressed in the ultimate seg- 
ment. Very faint indications of a hypapophysis occur in any of the 
first three caudals; in the fourth a cleft but sessile tubercle is seen, that 
leans forwards to rest upon the under surface of the centrum of the 
vertebre beyond; in the last two this process becomes much larger, 
and is evidently made up of the hemapophyses of the vertebre, for in 
each case it is pierced by a delicate hemal canal, while the true hypa- 
pophysis is still below and still exhibits the disposition to overlap the 
vertebrae beyond. The centra of the coccygeal segments of the spinal 
column in the Cathartid@, as among the class generally, are proccelian. 
In the coccygeal vertebra of G. papa we find the same general charac- 
ters present that we have just attributed to S. gryphus; the principal 
- differences are that the neural spines are more lofty and only the ulti- 
mate hypapophyses form a perfect hzeemal canal, the anterior ones being 
only grooved. Among the Vultures there is sometimes an extremely 
intimate relation existing between the first caudal vertebre and the 
last sacral, amounting to, in some cases, positive anchylosis. 
In Cathartes aura the neural canal is complete throughout the chain. 
and enters the pygostyle for some little distance; the hzemal canal 
does this also below, but this latter only passes through two of the hy- 
papophyses of the last two caudals, these processes being but feebly 
developed in the others. The diapophyses in this Vulture become 
gradually broader and shorter as we leave the sacrum. Catharista ex- 
hibits about the same peculiarities with regard to its caudal vertebre 
as we see in Cathartes aura. 
Mr. Lucas tells me that he counts seven caudal vertebre both in 
Otogyps calvus and G. bengalensis; he also kindly furnishes us with 
outline sketches of the pygostyles of these two Vultures, which we give 
below as we compare them with others. 
It will be observed that, as a rule the coccyx among the Cathartide 
is more or less parallelogramic in outline, with well-defined angles; on 
the other hand, among the Falconidw and the Owls and their allies 
this bony plate is drawn upwards and backwards into a rounded point; 
we give examples of this in the cuts, as well as exceptions to the rule. 
Neophron has a strong tendency Falcon-wards in this respect, less 
marked in Gypogeranus. . 
We also present the reader, in each case, except in the two outlines 
from Mr. Lucas, with a posterior view of this bone, which will show the 
great variability of outline of the pygostyle, better than any descrip- 
tion could do, however elaborate it might be made. An elliptical 
foramen, in some cases two (Gyparchus), pierce this plate at about the 
locality the last coccygeal vertebre fused with the one next behind, 
forming, as it were, a point that the process of osseous amalgamation 
failed to fill in. This feature is rare among the Falconide. Among 
