116 The Alligator and Its Allies 
is a pair of muscles; they are, as a whole, thin 
muscles that are widely separated and extend in 
an anteroposterior direction. Each arises by two 
parts which, however, are united at the pelvis. 
One of these parts is small at its beginning, is fairly 
thick, and is attached by a short tendon, immedi- 
ately over the pubis in front of the hip joint, to the 
ilium. The other part is not a very thick layer, and 
is attached, by a fairly long line, partly on the inner 
surface of the hindermost abdominal rib and partly 
on the outer border of the pubis. After the union 
of these two portions the muscle extends farther 
forwards and the fibers of the stronger portion 
spread out like a fan, becoming wider and thinner 
as they go forward and are at last attached partly 
to the pericardium, partly to the lobes of the liver of 
that side of the body. To be more exact, the fibers 
of the diaphragmaticus that lie nearest the middle 
line of the belly-wall extend forward as a fairly 
broad band to fuse with the pericardium. Most of 
the fibers of this muscle, however, are in close 
connection with a fibrous membrane which sur- 
rounds the liver parenchyma; this membrane is 
mostly very thin but it gradually becomes thicker 
towards the hinder border of the liver. Other 
muscle bands do not reach so far as the liver but 
are located near the middle line of the back; they 
are all, however, attached to an aponeurosis which 
passes over the upper, hinder border of the liver 
lobes to fuse with the fibrous capsule of the liver. 
