G4 THE VOYAGE OF H.M.S. CHALLENGER. 



5. Rectus capitis auticus major. 



Lf muscle droit et mm/en, Vicq d'Azyr, 1773, p. 582, JTo. 5. 



Kopfbieger (part of), Merrem. 



Dei- lange Kopfheuger, "Wiedemann, p. 76. 



Droit wiferieui- (1), Cuvier, vol. i. p. 238. 



Der mittlere Kopfhenger, Tiedemann, p. 28-5, No. 7. 



Grand droit anterieur, Meckel, vol. vi. p. 15, No. 3. 



Rectus capitis anticus major, Owen, p. 29. 



Rectus cajntis anticus major, Selenka, vol. vi. p. 100, No. 20. 



Droit anterieur, Gervais and Alix, p. 15. 



Attachments. — The rectus anticus major arises from the hypapophyses of the first, 

 second, and third, and from the lower surfaces of the bodies of the fourth, fifth, and sixth 

 cervical vertebrae, these origins being continuous along the middle line of the neck. 

 The fibres pass forwards, and are inserted by means of a stout tendon into the 

 hollowed triangular surface of the basi-occipital bone, immediately in front of the foramen 

 magnum. 



Action. — This muscle flexes the head upon the vertebral column. 



Relations. — The rectus major is separated from its fellow of the opposite side 

 liy the two common carotid arteries. Its outer surface is in contact with the origin of 

 the trachelo-mastoid, as well as with the insertion of the rectus capitis lateralis. 



Nerve siqyj^ly. — A branch from the anterior division of the second cervical nerve. 



Variations.- — In Spheniscus demersus, Spheniscus magellaniciis, and Sp)heniscus mendi- 

 cidus, the origin of the muscle is more extensive than in other species, extending 

 backwards to the lower surface of the body of the seventh cervical vertebra. 



G. Trachelo-mastoid. 



Der lange Kopfheuger, Tiedemann, p. 285, No. 8. 



Muscle No. 2, Meckel, vol. vL p. 13. 



Rectus capitis anticus minor, Owen, p. 29. 



Rectus capitis anticus minor, Selenka, vol. vi. p. 100, No. 20. 



Occipito-sous-eervical, Gervais and Ali.x, p. 15. 



Attachments. — The trachelo-mastoid is a thin fiat muscle, which arises fi-om the lower 

 surfaces of the bodies of the second, third, fourth, and fifth cervical vertebrae to the outer 

 side of the origin of the rectus capitis anticus major. The fibres pass obliquely forwards 

 and outwards, and are inserted by means of a short tendon into the nipple-shaped process 

 of bone immediately behind the external auditory meatus. 



Action. — This muscle flexes the skull upon the vertebral column, and directs the head 

 towards the side on which the niuscle acts. 



