n6 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. 



