SCHULTE, SEI WHALE. 17 



middle and receives in addition a small slip from the angle, the two origins being connected by a 

 sheet of fibrous tissue. Emerging in the interval between the deltoid and supraspinatus muscles, 

 its belly crosses the neck obliquely and is inserted into the whole length of the greater cornu of 

 the hyoid. These muscles all receive branches from the anser cervicalis. 



Suprahyoid muscles. Of these the geniohyoid is lacking and the mylohyoid has been 

 described in connection with the ventral pouch. The depressor mandibulse (posterior belly 

 of the digastric) is a large muscle placed obliquely below the external auditory meatus and the 

 broad extremity of the postglenoid process. It arises by mixed tendinous and fleshy fibres from 

 the dense connective tissue covering the mastoid region of the periotic under cover of the 

 sternomastoid. The belly expands in its course to the mandible where it is inserted into the 

 angle, chiefly at its caudal and ventral borders, but extending upon the lateral surface also 

 ectal to the attachment of the masseter. A large branch of the facial nerve emerges between 

 its belly and the postglenoid process, crosses the condyle of the jaw and the masseter muscle 

 and breaks up into branches for the panniculus. From this while in contact with its rostral 

 surface the nerve of the depressor is derived. The relations of this muscle to the sternomandibu- 

 laris and the anterior belly of the digastric have already been described. 



The stylohyoid is a ribbon like muscle arising from the mastoid region of the periotic 

 ventral and mesal to the depressor mandibulse and caudal to the orifice of the facial canal. It 

 is inserted into the body of the hyoid close to its junction with the anterior cornu and to the 

 adjacent portion of that process. Throughout its course it is closely applied to the lateral and 

 caudal aspect of the stylohyal cartilage. It is innervated by a branch of the facial nerve. 



The trapezius complex. These muscles derive their innervation from the spinal accessory 

 reinforced by branches from the ventral divisions of the cervical nerves. The sterno-mastoid 

 is a broad ribbon-shaped muscle, arising from the cephalic border of the sternum in its whole 

 breadth, where it abutts upon the origin of the pectoralis. It crosses the neck obliquely, narrow- 

 ing somewhat to its insertion by mixed tendinous and fleshy fibres into the squamosal and the 

 dense fibrous tissue which covers the mastoid. Here it is covered by a muscle of similar but 

 more superficial origin which directed caudad and ventrad towards the shoulder enters into 

 relation with the trapezius. At the shoulder this muscle resolves itself into two portions, a 

 deeper rounded belly which joins the trapezius and a superficial sheet which expanding is 

 inserted into the fascia along the rostral margin of the pectoral in its lateral half, extending to 

 the mesal border of the deltoid. The fascia of the posterior triangle of the neck is of consid- 

 erable density and in its course ventrad splits to enclose the sterno-mastoid in the usual manner. 

 Traced towards the thorax it becomes thickened along the cephalic margin of the pectoralis; 

 adjacent to the median line it is firmly attached to the sternum and laterad at the shoulder blends 

 with the dense sheath of the deltoid. Beyond this transverse line it continues upon the pecto- 

 ralis but is somewhat less dense and aponeurotic. The fasciculi of fascial insertion are obviously 

 representative of the cleido-mastoid, the slip joining the trapezius is the masto-humeralis. Of 

 the trapezius proper or cephalo-humeralis only the cephalic portion is represented. This is 

 a small fan shaped muscle arising from the dorsal aponeurosis of the cervical region without 

 direct attachment to bone. Its fibres are directed ventrad and slightly caudad converging to 

 a small rounded tendon, which after uniting with the larger masto-humeralis passes in front 

 of the shoulder to be inserted into the radial tubercle of the humerus on its ventral aspect 

 between the deltoid and the coraco-brachialis. Below this the tendon is continued by two 



