_Obliquus Abdominis Externus_ (Grand oblique, Aeusserer schiefer Bauchmuskel, Obliquus externus, Obliquus externus + internus + Serrati, Oblique descendens). Springs, with a flat prong, from the uncinate processes of the true ribs, thence it extends as a tendinous aponeurosis, near the lateral boundary of the ileo-costalis muscle, caudal-ward to the region of the twenty-third (crocodile) vertebra. From this fairly straight line of origin the muscle takes a sharply distoventral course and is inserted, at least in part, on the outer surface of the sternal part of the ribs of the tenth to sixteenth vertebræ, but does not reach the mid-ventral line. Under this chief part of the outer layer of the abdominal muscle lies a second, more band-like muscle mass which is also strong but of considerably less extent. It takes its origin from the outer surface of the middle third of the ribs. In the region of the twentieth vertebra it fuses with the upper layer, but inwardly reaches nearer the median line than the upper layer. _Obliquus Abdominis Internus_ (Petit oblique, Obliquus internus, Subcostalis). Arises as a flat muscle layer first with a strong tendinous portion from the anterior dorsal border of the os pubis and from the there-located cartilaginous inscriptio tendinea of the rectus; second, by a dorsal portion, with a short tendon, from the anteromedial surface of the pubo-iliac articulation from the pubis and ilium equally; third, from the dorsal anterior ends of the last named bones. It is inserted somewhat mediad to the lateral border of the rectus ventralis muscle that covers it on the outside. _Transversus Abdominis_ (Transverse, Oblique Bauchmuskel, Innerer Bauchmuskel, Transversus ventralis). This muscle springs by short, flat, indistinct forks from the inner surface of the proximal ends of the dorsal ribs but does not reach the centra of the vertebræ because of the long, broad transverse processes. Caudally the origin passes dorsalward to the lateral border of the quadratus lumborum muscle between which and the ileo-costalis muscle it is attached to the end of the transverse process. _Rectus Abdominis_ (Gerader Bauchmuskel + pyramidenförmiger Muskel, Pyramidalis, Rectus abdominis + pyramidalis). This muscle consists, in the Crocodilia, of several very distinct parts: