648 GEOLOGICAL SURVEY OF THE TERRITORIES. 
Of the pelvic limb—(P1. IV, Figs. 22, 39, 40, 42, 44, and 46).—The inner 
aspect of the upper extremity of the femur presents the usual globular 
head for articulation with the cotyloid ring of the pelvis. It is nearly 
sessile with the shaft, the neck amounting to almost nil. A shallow and 
inconspicuous excavation occurs on the head for the insertion of the 
ligamentum teres. The articular surface that originates with this hemi- 
spherical protuberance extends outwards over the summit of the bone, 
constantly spreading, until limited by the trochanterian ridge, in a 
plane with the outer aspect of the shaft; it occupies a slightly higher 
level than the head, and it is opposed to the anti-trochanter in the articu- 
lated skeleton. 
Anteriorly the trochanterian ridge and line are quite prominent, ex- 
tending a short distance down the shaft, to be lost on the general surface ; 
posteriorly it projects outwards horizontally from the articular surface, 
over a Shallow concavity thatis found immediately below, that presents 
at its base a circular foramen that leads to the hollow shaft, and is 
probably the pneumatic foramen, though the femur of this bird does: 
not have the appearance of a bone possessed of pneumaticity ; the ori. 
fice, if nutrient, is certainly situated in an unusual place, though we 
must confess that a careful search over the entire shaft with a powerful 
lens has failed to reveal any other opening. The trochanter minor is not 
represented. 
The shaft, for the greater part of its extent, is cylindrical, and decid- 
edly convex forwards, with a clean superficies, undivided by any inter- 
muscular ridges or lines, or if so, they are very faintly marked. 
The distal extremity of the femur enters largely intothe knee-joint, and 
is more bulky than the proximal extremity of the bone. It is directed 
backwards, and, as usual, is divided by an antero-posterior shallow in- 
tercondyloid notch, which is continued up the shaft anteriorly, as the 
‘‘rotular channel,” soon to disappear into internal and external condyles. 
The larger and lower external condyle is longitudinally cleft posteriorly, 
so as to afford an additional and outer condyloid surface for the head of 
the fibula, with which it articulates. 
A tuberosity is found behind, just above this cleft, and a few others, 
less prominent and situated more internally, are seen on this aspect of 
the bone, in the popliteal fossa. 
The limiting margin of the internal condyle is sharp and distinct. 
The ordinary features, as tuberosities and muscular lines and markings, 
usually sought for at this end of the bone in nearly all birds, are very 
feebly reproduced in our present subject. 
The proximal extremity of the tibia has a very interesting form, due 
to the prominence of the cnemial ridges. These are attached to the head 
of the bone, well above the horizontal articular surface for the condyles of 
the femur. Their superior border is continuous and convex upwards ; 
their inferior borders meet the shaft abruptly, and there terminate. 
Both of these wing-like processes are turned towards the fibular side of 
the bone, the procnemial process being the larger in every respect; and 
the ectocnemial sometimes is produced downwards into a very sharp 
and needle-like spine, a characteristic of other Oscines. They include 
between them a triangular concave and rather deep recess. The expan- 
sion supporting the superior articular surface projects over the shaft of 
the bone in all directions, being quadrilateral in outline, and having an 
articular facet for the fibula on the outer side, while in the middle of 
the surface above a tuberous spine of the tibia exists, with concavities 
on either side for the condyles of the thigh-bone. 
The shaft is remarkably straight, light, and hollow, though apparently 
