The Muscles gI 
Pterygo-maxillaris (Pterygoideus) (Pterygoid- 
ien, Aeusser Flugelmuskel, Pterygoideus externus, 
Pterygoideus internus). A large muscle which 
consists of two portions: the outer, weaker portion 
springs from the pterygoid process, the inner 
stronger part from the pterygoid fossa and ptery- 
goid process; they run together around the angle 
of the lower jaw, where they form a large, bulging 
fold. They are the chief muscles of this part of the 
body since the masseter is lacking and the tempo- 
ralis is weakly developed. 
Occtpito-maxillaris (Digastricus maxilla) (Nie- 
derzieher des Unterkiefers, Abaisseur ou l’analogue 
du digastrique, Senker des Unterkiefers, Aristotelis 
apertor oris, Digastricus, Aperator oris). Arises 
from the hinder border of the lateral occipital and 
is inserted at the hinder end of the lower jaw. 
Its course is from front to back. If the skull be 
stationary this muscle drops the lower jaw; if the 
jaw be fixed it raises the skull. 
MUSCLES OF THE VENTRAL SURFACE OF THE 
NECK 
Intermaxillaris and Sphincter Colli (Intermax- 
illaire, Mylo-hyoideus, Zwischenkiefermuskel, La- 
tissimus colli). This muscle consists chiefly of 
transversely running fibers, and has in its middle 
third a small, median, longitudinal raphe or apo- 
neurosis. In the posterior part of the neck it 
