MUSCLES OF THE BACK. 409 



cles, intended for the motion of these parts upon each other. 

 They are brought into view by the removal of the complexus. 



The Rectus Capitis Posticus Major, 



Arises, tendinous and fleshy, from the extremity of the spi- 

 nous process of the dentata, and is inserted into the inferior 

 transverse or semicircular ridge of the os occipitis, and into a 

 part of the continuous surface of bone below it. 



Its shape is pyramidal, the apex being below. It turns the 

 head, and also draws it backwards. 



The Rectus Capitis Posticus Minor, 



Is at the internal edge of the first. It arises, tendinous, from 

 the tubercle on the back part of the first vertebra, and is in- 

 serted into the internal end of the inferior transverse or semi- 

 circular ridge of the os occipitis, and into a part of the surface 

 between it and the foramen magnum. 



It is also pyramidal, with the apex downwards. It draws 

 the head backwards. 



The Obliquus Capitis Superior, 



Arises from the transverse process of the first cervical ver- 

 tebra, and is inserted into the outer end of the inferior semicir- 

 cular ridge of the os occipitis, behind the posterior part of the 

 mastoid process, and beneath the splenius muscle. 



It draws the head backwards. 



The Obliquus Capitis Inferior, 



Arises from the side of the spinous process of the dentata, 

 and is inserted into the back part of the transverse process of 

 the first vertebra of the neck. 



It rotates the first vertebra on the second. 



VOL. L 35 



