THE SKELETON 23 



ascending part of the mandible have wide depressions for 

 muscle insertion. 



The hyoid apparatus is craniad to the larynx to which it is 

 mobily attached. The osseous portions are the heavy basal 

 part (basihyal, hyoid bone) and its two pairs of cornua, which 

 extend mainly dorsolaterad. The lesser cornu of either side 

 is attached to the cranial, and the greater cornu to the caudal 

 end of the hyoid bone. 



b. VERTEBRAL COLUMN 



In all vertebrate animals, from fish to man, the individual 

 vertebrae are formed on the same general plan. Thus, the 



Fig. 4. — Diagram of a typical vertebra, caudolateral view. AA, anterior 

 articulating process; C, centrum (body); IN, intervertebral notch; LM, lamina; 

 NC, neural canal; P, pedicle; PA, posterior articulating process; SP, spinous 

 (neural) process; TP, transverse process, 



differences in the vertebrae of various animals and in the 

 different sections of the vertebral column of a single animal are 

 primarily due to modifications of the type- vertebra. A 

 typical vertebra (Fig. 4) has eight primary parts: a centrum 

 (body), a neural canal, two intervertebral notches, a 

 spinous process (neural spine), two pedicles, two laminae, 

 two transverse processes, two anterior (superior) articular 

 processes (prezygapophyses), and two posterior (inferior) 

 articular processes (postzygapophyses) . The pedicles of a 

 vertebra are the sides of the neural canal, and the laminae form 

 the roof or arch of this canal. The intervertebral notch with 



