MUSCULAR SYSTEM 



139 



between them; the]muscles thus lose their, intercostal character, 

 and form connected sheets, extending between the last pair of ribs 



FIG. 117. THE MUSCULATURE OF Siredon pisciformis. (Ventral view.) 



0, outer layer of the external oblique, passing into the fascia, which is shown 

 cut through at F ; Oh, inner layer of the same muscle ; He, rectus abdominis, 

 passing into the visceral musculature (sternohyoid) at Re 1 , and into the pector- 

 alis major at P ; Mh, Mh l , anterior and posterior portions of the mylohyoid, 

 which is cut through in the middle line, and removed on the left side, so as 

 to show the proper visceral musculature ; Ce, Ci, Ci 1 , external and internal 

 ceratohyoid : the former is inserted on to the hyoid (Hy) ; Add, adductor 

 arcuum branchialium ; C, constrictor arcuum branchialium ; Cph, portion of 

 the constrictor of the pharynx, arising from the posterior branchial arch ; 

 Dp, depressores branchiarum ; Gh, genio-hyoid ; Ph, procoraco-humeralis ; 

 Spc, supracoracoideus ; Cbb, coraco-branchialis brevis ; Clo, cloaca ; La, 

 linea alba. 



and the pelvic arch (e.g., the quadratus lumlorum, which lies close 

 against the vertebral column). 



