642 GEOLOGICAL SURVEY OF THE TERRITORIES. 
translucent, its outer and posterior borders receiving the greater share 
of osseous reénforcement, particularly in the vicinity of the antitro- 
chanter. 
Posteriorly, the ilium, slightly aided by the ischium, is carried out 
from an ilio-ischiadic, overhanging crest, as bony processes, with their 
points turned slightly inwards. 
These processes are strongly marked in another of our Oscines, Harpo- 
rhynchus rufus, a bird that has a strikingly angular and rather unique 
elvis. 
i: The antitrochanter is subelliptical in outline, and faces downwards, 
forwards, and outwards. The articular surface is produced downwards 
as far as the cotyloid cavity, upwards slightly above the general sur- 
face of the ilium, and is bounded posteriorly by the ischiadic notch. 
The foramen at the base of the hemispherical cotyloid cavity has so 
far absorbed the bone that really scarcely anything remains of it beyond 
a cylindraceous acetabular vacuity, the internal and external apertures 
being circles of equal diameter, and the femur consequently relying 
almost exclusively upon its fleshy and ligamentous attachments to re- 
tain its head in the ring. 
Sutural traces of the margins of the pelvic bones as the components 
of this osseous ring have entirely disappeared, having been obliterated 
during the pelvic consolidation. 
The ischiwm, for its major part, is like the iium—very thin, more par- 
ticularly so at its free posterior borders; joining with the ilium behind, 
it shuts off a large and elliptical ischiadic foramen, the superior arc of 
which is situated just beneath the ilio-ischiadie crest described above. 
The major axis of this ellipse is directed downwards and backwards. 
The posterior extremity of the ischium has an odd-appearing, foot-like 
termination, that is bent down to meet the pubis. 
This latter bone is an extremely slender style, that, immediately after 
assisting in the formation of the cotyloid ring, closes in a small, in fact 
the smallest of the group, subecircular obturator foramen behind; then 
running parallel with the ischium, by touching its further end, inclose, 
another long spindle-shaped vacuity ; it is finally produced beyond that 
bone by a pointed extremity, that curves backwards and inwards. 
It only remains now to say of the pelvis, as far as its internal aspect 
is concerned—after what we have said in regard to its extreme lightness, 
its translucency, its sacrum, and its borders—that, in general, superior 
convexities cause or create internal concavities, and vice versa. It is ca- 
pacious, and the various bones that compose it thoroughly anchylosed 
together. 
There are seven coccygeal or caudal vertebre, rarely only six, and the 
pygostyle; they are in the skeleton so arranged and articulated that they 
have, as a whole, a gentle curve upwards, terminated by the quadrate 
‘““coceygeal vomer.” 
These segments are all free, being ‘easily individualized, even before 
maceration, by simple section of the ligaments that bind them together. 
The subcircular neural canal, that passes through them, almost capil- 
lary in its dimensions, terminates without passing into the pygostyle. 
There is no hemal canal developed, and indeed hypapophyses are 
found as stunted tubercles only on the last two or three vertebre. 
A neural spine is developed on each, as a prominent and curved pro- 
eos oe forwards; this spine is wanting, however, on the last 
caudal. 
Of the lateral apophyses the transverse processes seem to be the only 
ones entitled to any consideration; these, as broad, flattened lamina, 
