326 PROCEEDINGS OP THE CANADIAN INSTITUTE. 



5. Pharyngo-clavicularis Internus, (No. 37, Cuv. ; Branchi- 



retractor, Ow.) (Fig. 4, Ph. In.) 



A thin band-like muscle, arising from the upper surface of the 

 clavicle near the middle line, and is inserted slightly behind the 

 preceding. 



Innervation. — Same as preceding. 



Action. — Same as pharyngo-clav. ext. 



B. — Dorsal Muscles. 



6. Musculi Levatores Bhanchiales, (tfos. 30-33, Cuv. ; Branchi- 



levatores and Masto-branchialis, Ow. ; Lev. branch, ext. and iwi., 



Vetter.) 

 These may be exposed from the inside by the dissection required 

 for the pharyngo-claviculares, or from the outside by removing the 

 opercular and hyomandibular apparatus and detaching the membrane 

 extending from the upper moieties of the gill arches to the under sur- 

 face of the skull. They are seven in number, three being attached 

 to the superior pharyngeal. 



(a) Arises from a concavity on the posterior part of the under sur- 

 face of the pterotic. It is a round, stout muscle, which passes almost 

 directly downwards, and is inserted into the posterior portion of the 

 upper surface of the superior pharyngeal. 



(b) Arises from the under surface of the pterotic in front of (a). 

 It is broad and thin, and runs obliquely forwards to be inserted into 

 the cartilages at the extremity of epibr. i. 



(c) Arises from the pterotic in front of and slightly lower than 

 (6). It passes down between epibrs. ii. and iii., and is inserted into 

 the anterior portion of the upper surface of the superior pharyngeal. 



(d) Arises from the sphenotic immediately below the articulation 

 of the hyomandibular. It passes down between epibrs. ii. and iii.,, 

 and is inserted just behind (c) (with whose fibres it intermingles some- 

 what below) into the antero-external portion of the upper surface of 

 the superior pharyngeal. 



(e) Is closely related to (d) lying on its outer surface. They arise 

 together, and (e) passing downwards, is inserted into epibr. iii. at the 

 base of its process. 



(/ ) Arises in front of (d) and (e) from the sphenotic, and is inserted 

 into the inner extremity of the anterior surface of epibr. ii. 



