182 Anatomy of the; Rabbit. 



where they form thick muscular pads interposed between 

 the mammillary and accessory process. The last slip is 

 attached to the crest of the ilium. 



2. The following muscles constitute an occipital group, composed of 

 short muscles arising from the atlas and axis and inserted on the atlas 

 and the occipital portion of the skull. 



(a) The rectus capitis posterior superficialis. Origin: Spinous 

 process of the atlas. Insertion: External occipital pro- 

 tuberance. 



(b) The obliquus capitis superior. Origin : Transverse process of 

 the atlas. Insertion: Lateral surface of the occipital pro- 

 tuberance. 



The foregoing muscles should be divided. 



(c) The rectus capitis posterior minor. Origin : Posterior tubercle 

 of the atlas. Insertion: External occipital protuberance. 



(d) The rectus capitis posterior major. Origin : Spinous process 

 of the epistropheus. Insertion: Laterally on the supra- 

 occipital bone. 



(e) The obliquus capitis inferior. Origin : Spinous process of the 

 epistropheus. Insertion: Dorsal surface of the transverse 

 process of the atlas. 



(f) The rectus capitis lateralis. Origin: In common with the 

 obliquus capitis superior, which covers it. Insertion: Base 

 of the jugular process of the occipital. 



3. Muscles of the lateral and ventral surfaces of the neck. 



(a) The scalenus anterior. Origin: Transverse processes of the 

 four posterior cervical vertebrae. Insertion : First rib. 



(b) The scalenus medius. Origin: Transverse process of the 

 fifth cervical vertebra. Insertion: Lateral surfaces of the 

 third to fifth ribs. 



(c) The scalenus posterior. Origin: Transverse processes of 

 the fourth to sixth cervical vertebrae. Insertion: First rib. 



(d) The scalenus medialis. Origin : The sternum at the point of 

 attachment of the first rib. Insertion : Middle of the ventral 

 portion of the first rib. 



The foregoing muscles, comprising the scalenus group, are destroyed 

 by the removal of the ventral thoracic wall (p. 172). 



(e) The longus colli. Origin: Bodies of the first six thoracic 

 vertebrae. Insertion: The muscle passes forward on the 

 ventral surface of the bodies of the vertebrae, giving off 

 insertion fibres, and also receiving strands of origin. It 

 terminates on the anterior tubercle of the atlas. 



(f) The longus capitis is partly fused with the foregoing muscle, 

 but its origin is in a more lateral position from the trans- 

 verse processes of the first six cervical vertebrae. Insertion: 

 Sphenooccipital synchondrosis. 



