_The Diaphragm_ (Diaphragmaticus, Zwerchfell, Bauchfellmuskel). Closely inclosed between the skin and muscle of the abdomen, in the Crocodilia, 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, immediately 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 surrounds 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. To the sternum as to the ribs is only a small part of this muscle attached. Between the two above described muscles is found a space which is filled, in great part, with a fibrous membrane that binds the two muscles together. This membrane begins very thin and without a marked boundary behind the kidneys; it runs forward directly under them and the dorsal wall of the body, becoming gradually thicker, though never very thick, and fuses, laterad to the kidneys, with the above-mentioned aponeurosis of the two diaphragmaticus muscles. Thence this aponeurosis goes to the upper, hinder side of the liver where it becomes fairly thick. One thus finds in front of the stomach a fibrous membrane, belonging to the diaphragmaticus, which is pierced by the œsophagus and by a fairly large space that extends around the œsophagus and between it and the liver. This membrane fastens the liver to the œsophagus.