96 ANNALS NEW YORK ACADE3IY OF SCIENCES 



(b) Capiti-mandibularis medius. 



= Temporalis. 



(c) Capiti-mandibularis profundus. 



= External pterygoid of Mivart. 

 = Pterygoideus externus, Hoffmann. 

 = Pterygo-mandibularis, Hoffmann. 

 = Internal pterygoid, Sanders. 

 = Entopterygoid, Sanders. 

 = Pterygoidien externe, Cuvier, Dumeril. 

 Pterygoideus anterior. 



= Pterygoidien interne, Cuvier, Stannius. 



= Pterygoideus internus, Hoffmann. 



= Internal pterygoid, Mivart, Edgeworth. 



= External pterygoid, Sanders. 



= Ectopterygoid, Sanders. 



= Pterygo-mandibularis, Bradley, Watkinson. 



= Pterygoideus, Versluys. 



MUSCLES OF THE DEPRESSOR OR DIGASTRIC GROUP 

 (INNERVATED BY YII) 



Depressor mandibul^e. 



MUSCLES OF THE ADDUCTOR OR TEMPORAL GROUP 

 (INNERVATED BY V^X 



Capiii-mandihularis. — This is the large temporal muscle which is 

 divided into three slips in this paper. 



(a) Capiti-mandibularis superficialis (C. m. s.). — This masseter slip 

 is lower down on tlie outside of the mass. It arises on the quadrate, squa- 

 mosal and quadratojugal. Its fibers extend over the fibers of the temporal 

 slip and h\em\ with them to be inserted on the coronoid and the dorsal 

 edge of the mandible. They extend down on the outer face to quite an 

 extent, which is not common in the reptiles, as usually the insertion is 

 entirely on the inner side of the mandible. They also extend down on 

 the inner side. This crossing of the temporal and the masseter slips 

 gives two pulls to the mandible, a straight dorsal and a posterior one. 



(b) Capiti-mandibularis medius (C. m. m.) . — The temporal or median 

 slip fills the temporal fossa; it arises on the parietal, postfrontal and 

 squamosal. The supratemporal fossa is large and the parietal is extended 

 out, so as to furnish a large insertion for this part of the muscle. It ex- 

 tends down l)etween the masseter and the inner slip to be inserted on the 

 mandible. 



