MUSCULAR SYSTEM OF THE RED HOWLING MONKEY 5 



A tubercle, a depression, a roughened area or a sharp short crest can 

 be seen at this point in the zygomatic process of the maxilla. These 

 fascicles form a gleaming lamina in the upper rostral quadrant of the 

 muscle. Their direction is almost vertical along the anterior border, 

 but increasingly oblique as they aim toward the angle and dorsal edge 

 of the ramus. Posterior fibers arise from the rear fourth of the arch. 

 They are muscular at the middle of the zygoma, and aponeurotic 

 nearer to the fossa mandibularis, where they are organized into a thin 

 but resistant sheet which is continuous without interruption with the 

 capsule of the temporomandibular joint. The fleshy fibers reach the 

 basis mandibulae and the margins of the angle and ramus follo^^'ing a 

 progressively more horizontal duection. They are connected through 

 a tough fibrous raphe \vith those of m. pterygoideus medialis. Deeper 

 bundles fasten to most of the lower three-fourths of the external sur- 

 face of the ramus. The orally concave rostral margin of the muscle 

 covers the second upper molar, a fact already indicated by Starck 

 (1933). The mandible of strong males has a depression corresponding 

 to the insertion of the deeper fibers. 



Figure 2. — Muscular attachments in the mandible (1, m. pterygoideus lateralis; 2, m. 

 constrictor pharyngis superior; 3, m. pterygoideus medialis; 4, m. digastricus; 5, m. 

 mylohyoideus; 6, m. buccinator; 7, m. temporalis). 



