86 The Alligator and Its Allies 
This dorsal end, which forms the ventral side of the 
acetabulum, is divided into two distinct articular 
surfaces by a deep, rounded notch; the posterior 
and larger surface articulates with the ilium, the 
anterior surface about equally with the pubis and 
epipubis. 
The pubis (3), which is much the smallest ele- 
ment of the pelvis, is a small mass of cartilage 
lying between the ilium above and the ischium 
below. It forms a small part of the anterior wall 
of the acetabulum. 
The epipubis (4) is a slightly arched bone, some- 
what enlarged at its proximal end where it unites 
with the ischium, and flattened out into a fan- 
shaped extremity, where it is united with its fellow 
and with the last pair of abdominal ribs by the 
broad, thin sheet of cartilage or fibrous tissue noted 
im connection with the abdominal ribs. As men- 
tioned above, it is called by Wiedersheim and 
others the pubis. Near the center of the acetabu- 
lum there is a small foramen. 
The posterior limb (Fig. 29) consists of the usual 
divisions—thigh, shin, and foot. The femur (f) 
is a bone of the same general outline as the humerus, 
though slightly longer and heavier. The head, for 
articulation with the acetabulum, is rather hemi- 
elliptical than hemispherical in shape, the long 
axis of the ellipse being vertical. The distal 
enlargement is of at least as great, if not greater, 
bulk than the proximal and shows some indication 
