55

35

The carocoid is the strongest bone: its inferior expanded extremity presents an arti-
cular convexity, adapted to the sternal groove before described.

The scapula reaches to the third rib : it is a simple narrow plate of bone, slightly
curved and expanded at both ends, but chiefly at the humeral articulation. Its length
is one inch.

The humerus is a slender, cylindrical, styliform bone, slightly bent, 1 inch 5 lines in
length ; slightly expanded at the two extremities, most so at the proximal end, which
supports a transverse oval articular convexity, covered with smooth cartilage, and
joined by a synovial and capsular membrane to the scapulo-coracoid articulation. A
small tuberosity projects beyond each end of the humeral articular surface. The distal
end of the humerus is articulated by a true but shallow ginglymoid joint with the rudi-
mental bones of the antibrachium, and both the external and internal condyles are
slightly developed.

The radius and ulna are almost straight cylindrical slender bones, each 9 lines in
length. A feebly developed olecranon projects above the articular surface of the ulna.
There is a minute carpal bone, two metacarpals, and a single phalanx, which supports
the long curved obtuse alar claw. The whole length of this rudimental hand is 7 lines,
including the claw, which measures 3 lines and a half. A few strong and short quill-
feathers are attached by ligament to the ulna and metacarpus.

The iliac bones in size and shape resemble those of the Struthious tribe : the length
is 4 inches and 3 lines. the outer surface presents a slight concavity anteriorly which
gradually passes into a convexity posteriorly, the two surfaces not being separated by
the transverse elevation observable above the acetabulum in the four large Struthious
birds. A distinct epiphyseal piece of bone, of a compressed and triangular form,
is wedged in between the posterior extremity of the ilia and the first three caudal
vertebrae.

The ischium extends backwards, parallel with the sacrum, in the form of a thin plate
of bone which slightly expands to its free extremity, which is truncated.

The pubic element is a slender bony style, connected by ligament to the end of the
ischium, but attached by bone at its acetabular extremity only. A short pointed process
extends from the anterior margin of the origin of the pubis. In comparing the pelvis
of the Apteryx with that of the large Struthious birds, we find that the ischia do not meet
below the sacrum as in the Rhea, but are more distant from that and the iliac bones than
in any of the Struthious birds ; the pubic bones are not joined together at their distal
extremities as in the ostrich ; the extremities of the ischia are not anchylosed to the
superincumbent ilia as in the Cassowary. It is the Emeu, which comes nearest to the
Apteryx in the structure of the pelvis, but it also differs in the complete bony boundary
of the foramen which transmits the tendon of the oturator internus, and which is com-
pleted posteriorly by ligament in the Apteryx.

The acetabulum communicates, as usual, by a wide opening with the pelvis: a surface

F2