OCR Text |
Show 1894.] ANATOMY OF PALAMEDEA CORNUTA. 543 Ileo-coccygeus.-This muscle is divided into two slips. The outer thicker slip is entirely fleshy; it arises from the dorso-medial face of distal ileum only. It is inserted on to the outermost rectrix. The inner thinner portion of the muscle is also entirely fleshy. It arises from the sacro-ileal ligament. It is only one quarter the size of the outer muscle. Pubo-coccygeus externus.-This muscle is a flat band with its wide and fleshy origin from outer posterior dorsal margin of the pubis behind its connection with ischium. It narrows to be inserted fleshy upon the under surface of the external rectrix. Pubo-coccygeus internus.-It arises from the ends of the pubis and ischium under the last-named muscle. It is inserted onto the underside of the last one or two caudal vertebrae. Depressor coccygis.-It arises partly from the transverse process of the last sacral vertebrae, and partly from adjacent surface of ileo-sacral ligament. It is inserted on to the transverse processes and haemapophyses of last three or four caudal vertebrae. Shoulder-girdle. Rhomboideus externus.-This muscle arises tendinously, the width of the tendinous part being about the same as that of the muscular part from the last cervical vertebra and all the dorsal except the last. The fibres run forwards to be inserted fleshy along the whole length of the scapula. The extreme front part of the muscle is double, and may represent a portion of the cucullaris. Rhomboideus internus.-This muscle arises tendinously, but has much less tendon than the last. The fibres run backwards, both the origin and insertion of this muscle being shorter than in the case of the externus. Serratus anticus.-This consists of three portions. The first arises from the last incomplete and from the first complete rib. It is inserted on to the scapula between the two parts of the sub-scapularis. The second part arises from the upper part of last incomplete rib and runs to the scapula. The third part arises from the upper part of the first complete rib. Serratus posticus.-Pars metapatagialis arises from the fifth complete rib. Part 2 consists of two digitations arising from complete ribs 3, 4, 5, at the points where the uncinate processes should be and from the fascia between them. Insertion is on to the tip of the scapula. Latissimus dorsi.-This muscle, as usual, consists of two parts, which are quite separated by a wide space. The anterior part arises from dorsals 1 to 3; it has a broad and fleshy insertion one inch long ending just before the end of the deltoid. The posterior division of the muscle is narrow and strap-like ; it arises from the last three dorsals and from the anterior margin of the ileum. It bifurcates just before its insertion ; part goes to form a meta- |