_Action._--The two muscles hold the scapulæ 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 caudoventrad 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 surface with the rhomboideus, splenius, occipitoscapularis, levator scapulæ, 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 considered as forming a single muscle, the cephalohumeral, or cephalobrachial.
=M. occipitoscapularis= (or levator scapulæ 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 is wedged between the rhomboideus dorsally and the levator scapulæ ventrally.
_Insertion_ either into the inner surface of the levator scapulæ near its dorsocranial border at its insertion or into the scapula near the coracovertebral angle (Fig. 78, _f_) or into both. Its fibres are very closely related to those of the rhomboideus.
_Relations._--By its outer surface with the clavotrapezius (Fig. 68, _d_) and acromiotrapezius (_h_). At its insertion it is often overlaid by either the rhomboideus or the levator scapulæ or both. By its inner surface with the splenius (Fig. 73, _b_). Its caudal third is wedged between the rhomboideus and the levator scapulæ.