ulum (Section 77).

Section 82. The fore-limb (pectoral limb) consists of an upper arm
bone, the humerus (hum.) the distal end of which is deeply
excavated by the olecranon fossa (o.f.) as indicated by the dotted
lines; of two bones, the ulna (u.) and radius (r.) which are firmly bound
by ligament in the position of the figure (i.e., with the palm of the hand
downward, "prone"); of a number of small bones (carpalia), the carpus
(c.); of a series of metacarpals (mc.); and of three digits (= fingers)
each, except the first, or pollex, of three small bones-- the phalanges,
only the proximal of which appear in the figure. The ulna has a
hook-like head, the olecranon (o.) which distinguishes it easily from
the distally thickened radius. The limb is attached to the body through
the intermediation of the shoulder-blade (scapula, sc.) a flattened
bone with a median external ridge with a hook-like termination, the
acromion (acr.). There is also a process overhanging the glenoid
cavity (g.) wherein the humerus articulates, which process is called
coracoid (co.); it is ossified from two separate centres, and represents
a very considerable bone in the bird, reptile, and frog. Along the dorsal
edge of the scapula of the rabbit is unossified cartilage, which is
called the supra-scapula (s.sc.). In man there runs from the acromion
to the manubrium of the sternum a bone, the collar-bone or clavicle.
This is represented by a very imperfectly ossified rudiment in the
rabbit. The scapula and clavicle, the bones of the body connected
with the fore-limb, are frequently styled the pectoral girdle, or
shoulder-girdle; this name of girdle will appear less of a misnomer
when lower vertebrate types are studied.

Section 83. The hind limb and its body bones-- pelvic limb and
girdle-- are shown in Figure 2. The limb skeleton corresponds
closely with that of the fore-limb. The femur (fe.) answers to the
humerus, and is to be distinguished from it by the greater
distinctness of its proximal head (hd.) and by the absence of an
olecranon fossa from its distal end. The tibia (ti = the radius) is fused
for the distal half of its length with the fibula (fb. = ulna). A tarsus
(tarsalia) equals the carpus.* Two of the proximal tarsalia may be
noted: one working like a pulley under the tibia, is the astragalus
(as.); one forming the bony support of the heel, is the calcaneum
(ca.). There is a series of metatarsals, and then come four digits of
three p