n8 THE MUSCLES. 



Near its origin its caudal border touches the outer surface of the 

 spinotrapezius (_/'). Its cranial border is overlaid near its 

 insertion by the levator scapulae ventralis (_/") and is closely 

 related to the caudal border of the clavotrapezius (d) near its 

 origin. 



Action. The two muscles hold the scapulae together. 



M. clavotrapezius (Fig. 68, d}. The clavotrapezius 

 (cranial part of the human trapezius) is a flat muscle passing 

 from the lambdoidal crest and middorsal line to the clavicle 

 and covering the side of the neck. 



Origin. The medial half of the lambdoidal crest and the 

 middorsal line between the crest and the caudal end of the 

 spine of the axis. The fibres are parallel and pass caudoven- 

 trad so that the muscle covers the ventral surface of the neck 

 caudally and fills the concavity at the front of the shoulder. 



Insertion into the clavicle and into a raphe between the 

 clavotrapezius and the clavobrachial (e) muscles. This raphe 

 extends along the clavicle and for some distance laterad of it. 

 The muscle is partly continuous with the clavobrachial (e). 



Relations. Outer surface with the platysma, and at its 

 craniomedial angle with the levator auris longus. Inner sur- 

 face with the rhomboideus, splenius, occipitoscapularis, levator 

 scapulae, cleidomastoid, and supraspinatus. The cranial edge 

 touches the sternomastoid. The caudal border touches the 

 acromiotrapezius near the origin. 



Action. Draws the scapula craniodorsad. 



This muscle and the clavobrachial (e) are sometimes con- 

 sidered as forming a single muscle, the cephalohumeral, or 

 cephalobrachial. 



M. occipitoscapularis (or levator scapulae dorsalis or 

 rhomboideus capitis) (Fig. 73, a). The occipitoscapularis 

 (equivalent to a part of the human rhomboideus) is a slender 

 flat muscle from the lambdoidal ridge to the coracovertebral 

 angle of the scapula. 



Origin, the medial half of the lambdoidal ridge beneath the 

 clavotrapezius (Fig. 68, d}. The origin does not extend quite 

 to the middle line. The muscle passes almost directly caudad. 

 Its caudal end is thicker and narrower than the cranial end and 



