II.] 



THR SPINAL SKELETON; 





73 



\vhich descend (the spine being horizontal) on each side from 

 the soft representative of the backbone, and are connected by 

 transverse bars extending in the direction of the spine. 

 The hindermost (most post-axial) ventral part of this basket 

 supports the heart. 



FIG. 82. STERNUM OK COMMON MOLE (Talpa enroptea). 

 fs, manubrium ; JUS, mesosternum ; xs, xiphisternum ; c, point of attachment of 



the clavicle. 

 (From Professor Flower s "Osteology.") 



In some Sharks there are similar cartilaginous arcs (though 

 much less developed) supporting the external borders of the 

 partitions between the gills. 



