1890.] HELODERMA SUSPECTUM. 165 



This muscle is superficial and closely applied to the serratus pro- 

 fundus, 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 s. profundus expends its 

 greater width above it, having a higher insertion upon the supra- 

 scapula. 



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 en- 

 croachment 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. Sterno-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 some- 

 what 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 subscapularis. 



28. Sterno-coracoideus internus profundus. — As its name indi- 

 cates, this muscle is deep to the one just described. It arises from 

 the inner chest-wall, and 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 sterno-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 Cbamselon. 

 Following Fiirbringer, they have also been termed the m. sterno- 

 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 in der 

 Kegel durch zwei an der Innenflache des Brustbeins und ventralen 



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