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Show 1890.] HELODERMA SUSPECTUM. 165 This muscle is superficial and closely applied to the serratus profundus, its fibres having the same direction almost throughout its length ; it is so^ inserted, however, that the wider s. profundus extends beyond it, both beyond its superior and inferior borders posteriorly ; while anteriorly, the lower margins of these two muscles are nearly in the same line, and the 5. profundus expends its greater width above it, having a higher insertion upon the suprascapula. 25. Serratus profundus.-As I have already pointed out in the description of the s. superficialis, the present muscle lies immediately beneath the same. It arises from the superior extremities of the first two sternal ribs ; from the lower end of the last cervical rib ; and from the lower end of the first dorsal rib, as well as from the fascia stretching between these parts of the skeleton. Its fibres taking a course forwards and upwards, they become inserted upon the entire posterior border of the suprascapula, making slight encroachment upon the adjacent internal surface of the same bone. 26. Serratus tertius.-This is the third muscle of the Serrati group, and it arises by fleshy digitations from the fascia between the last two cervical ribs (this part of the origin is very weak), from the free extremities of the penultimate and next two anterior cervical ribs. From this origin the muscle is thrown upwards as a thin, fleshy sheet, covering the thoracic aspect of the corresponding scapula and suprascapula, to finally insert itself along the free, inner margin of the last-named bone, for the anterior four fifths of its superior edge. 27. Stemo-coracoideus internus superficialis.-To examine this muscle from the ventral aspect one must disarticulate the coracoid and the sternum, as the muscle lies within the thoracic cavity. It will be found to arise from the externo-dorsal surface of the sternum ; from the anterior border of the same surface and from one or two of the sternal ribs and the fascia between them, upon the same side. From this origin its fibres pass directly forwards, converging somewhat as they do so, to become inserted into the coracoid, on its inner aspect and near its lower anterior border, immediately in front of the subscapulars. 28. Stemo-coracoideus internus profundus.-As its name indicates, this muscle is deep to the one just described. It arises from the inner chest-wall, aud from the thoracic aspect of the posterior moiety of. the sternum beyond it ; when, converging, its fibres becoming tendinous, it finally inserts itself upon the inner surface of the coracoid, above and somewhat anterior to the stemo-coracoideus internus superficialis. Both these muscles were found to be present in Liolepis belli by Sanders, while Mivart describes but one of them as the " sterno-coracoid " as occurring in Parson's Chamselon. Following Fiirbringer, they have also been termed the m. stemo-coracoideus internus superficialis and m. sternocoracoideus internus profundus by Hoffmann, who has said of them that " Die Mm. sterno-coracoidei interni superficialis und profundus werden Regel durch zwei an der Innenflache des Brustbeins und ventralen |
