I. The rectus ventralis, the chief part, arises as a fleshy tendon from the sternum and from the ventral part of the last rib that reaches the sternum, and extends with direct longitudinal fiber-bundles of equal mass over the ventral third of the body back to the pelvis. It is inserted as a fleshy tendon on the anterior border of the pubis and more laterally is united, together with the obliquus internus muscle, chiefly to the last abdominal ribs which arise as an ossification of the last strongly developed inscriptio tendinea. This muscle-band, which unites with that of the opposite side to form the linea alba, is divided metamerically by seven distinct inscriptiones tendinea. These inscriptiones are the above described abdominal ribs which consist of bony connective-tissue without a trace of cartilage cells. These so-called abdominal ribs, then, are not true ribs but are ossifications of the tendinous structures. II. From the anterior border of the os pubis and the last strong inscription, also, to some extent, as a process of the preceding part, begins a new fleshy layer which, extending in diminishing size backward, is inserted by a strong tendon on the distoventral end of the ischium somewhat laterad to the symphysis. It is the muscle that is called by different authors the pyramidalis. III. Rectus lateralis. About in the region of the twentieth vertebra, or at the level of the fifth inscription, a fleshy band-like muscle separates itself from the edge of the rectus muscle and the obliquus internus muscle and passes over to fuse with the ischio-coccygeus muscle. IV. Rectus internus. On the inner surface of the rectus ventralis, from which it is separated by the intervening aponeurosis of the rectus muscle, appears a muscle lying on the outside of the diaphragmatic muscle. It extends as a broad band from the breast to the anterior border of the os pubis, with longitudinally directed fibers, to half the width of the rectus ventralis muscle. _Intercostales_ (Zwischenrippenmuskeln). The intercostal muscles in the Crocodilia are, in proportion to the strength of the ribs, of slight structure; they extend only from rib to rib and are, therefore, very short, though fairly thick. They, as usual, consist of the outer muscles with a direction like that of the external oblique, and of an inner muscle extending in the opposite direction, _i.e._, at right angles. The internal muscles are especially well developed in the breast region and pass over into the internal oblique muscle. _Quadratus Lumborum_ (Carré des lombes, Viereckiger Lendenmuskel, Psoas major). A strong, thick muscle that springs from the inner surface of the transverse processes and bodies of the last six presacral and the first sacral vertebræ. The muscle diminishes as it passes in a caudoventral direction and is inserted with a strong tendinous band to the trochanter femoris.