MUSCULAR SYSTEM 



139 



between them; the'jmuscles thus lose their intercostal character, 

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



Fig. 117. — The Musoitlature of Siredon pisciformis. (Ventral view.) 



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

 cut through at F ; Ob, inner layer of the same muscle ; Re, rectus abdominis, 

 passing into the visceral musculature (sternohyoid) at Be^, and into the pector- 

 alis major at P ; Mh, Mh?-, 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, Oi^, external and internal 

 ceratohyoid : the former is inserted on to the liyoid (Sy) ; Add, adductor 

 arcuum branchialium ; G, 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-brancliialis brevis ; Clo, cloaca ; La, 

 linea alba. 



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

 against the vertebral column). 



