_a_, M. frontoscutularis; _b_, M. masseter; _c_, M. sternomastoideus; _d_, M. clavotrapezius; _e_, M. clavobrachialis; _f_, M. levator scapulæ ventralis; _g_, M. acromiodeltoideus; _h_, M. acromiotrapezius; _i_, M. spinodeltoideus; _j_, M. spinotrapezius; _k_, caput longum of M. triceps brachii; _l_, caput laterale of M. triceps brachii; _m_, M. latissimus dorsi; _n_, M. xiphihumeralis; _o_, M. pectoralis minor; _p_, M. obliquus abdominis externus; _q_, M. sartorius; _r_, M. tensor fasciæ latæ; _s_, M. caudofemoralis; _t_, M. biceps femoris; _u_, M. semitendinosus; _v_, M. extensor caudæ lateralis; _w_, M. abductor caudæ externus; _x_, M. flexor caudæ longus; _y_, lumbodorsal fascia, superficial layer; _z_, fascia lata. 1, parotid gland; 2, submaxillary gland.] _Relations._--Outer surface with the cutaneus maximus, the integument and platysma. Inner surface with a mass of fat partially covering the rhomboideus; with the occipitoscapularis, spinotrapezius, supraspinatus, levator scapulæ, and splenius. Near its origin its caudal border touches the outer surface of the spinotrapezius (_j_). Its cranial border is overlaid near its insertion by the levator scapulæ ventralis (_f_) and is closely related to the caudal border of the clavotrapezius (_d_) near its origin. _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.