2o6 Anatomy of the Rabbit. 



(b) The basioclavicularis (basiohumeralis). Origin: Basiocci- 

 pital bone. Insertion : Lateral third of the clavicle and the 

 cleidohumeral ligament. 



(c) The levator scapulae major. Origin: Cartilage union of 

 basioccipital and basisphenoid (sphenooccipital synchon- 

 drosis). Insertion: Metacromion. 



The superficial cervical artery (p. 257) passes obliquely forward 

 and outward under cover of these muscles, ramifying beneath the superior 

 portion of the trapezius in the fat-mass of the side of the neck. Its 

 ascending cervical branch passes forward on the lateral surface of the 

 external jugular vein. 



(d) The trapezius. Origin in two portions : 



Superior (cervical) portion: External occipital protuber- 

 ance and dorsal ligament of neck (ligamentum nuchae). 

 Insertion : Metacromion and supraspinous fascia. 

 Inferior (thoracic) portion. Origin: Spinous processes of 

 the thoracic vertebrae and the lumbodorsal fascia. Inser- 

 tion: Dorsal half of the scapular spine. The muscle forms 

 a broad triangular sheet on the dorsolateral surface of the 

 shoulder. 



The levator scapulae major, basioclavicularis, and trapezius should 

 be divided. On the ventrolateral surface of the superior portion of the 

 trapezius and levator scapulae major may be found nerves from the 

 ventral rami of the third, fourth and fifth cervical spinal nerves. The 

 great auricular nerve (n. auricularis magnus) passes from the third to 

 the ear. 



(e) The rhomboideus minor. Origin: Ligamentum nuchae. 

 Insertion: Anterior two-thirds of the vertebral border of the 

 scapula. 



(f) The levator scapulae minor. Origin : Mastoid and supra- 

 occipital portions of the skull. Insertion: Medial surface of 

 the inferior angle of the scapula. 



(g) The rhomboideus major Origin: Spinous processes of 

 the first seven thoracic vertebrae. Insertion: Posterior 

 third of vertebral border. The rhomboidei are almost 

 continuous. 



By dividing the rhomboidei the scapula may be displaced laterad. 

 The operation is facilitated by dividing the latissimus dorsi, the re- 

 lations of which should, however, first be noted (2, a). 



