38 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
The innervation of the two preceding muscles is from the ventral 
ramus of the first spinal nerve, which passes between m. sterno- 
hyoideus and m. omohyoideus to supply both (Plate 7, fig. 22; Plates 
2, 3). - 
4, MUSCLES OF THE JAW AND NECK. 
| 
M. pterygo-mandibularis (Bradley). This is the muscle (Plates 5, 
6, figs. 14-19, pt-md.) generally described as the external ptery- | 
goid. Itis best seen from the ventral side with the roof of the pharynx 
removed (Fig. J). Its origin is along the entire posterior edge of the 
main portion of the pterygoid bone, and chiefly by means of a strong 
tendinous fascia that is continuous with the muscle sheath on the 
ii id 
jor --- 
for.V ~ 
prc pi-qd. ‘ pisph.p ba’oce.' besph. 
Fig. H. Hic. & 
Fic. H.— Right lateral aspect of a portion of the skull to show attachments 
of the deeper muscles, m. pterygo-parietalis and m. pterygo-sphenoidalis 
posterior. ‘ 
Fic. I.— Ventral aspect of a portion of the right half of the skull with man- 
dible removed to show m. pterygo-mandibularis. This really covers the 
m gpterygo-sphenoidalis posterior, but is slightly displaced to show the 
position of the latter. 
ventral side. The most posterior fibers have a fleshy origin along the 
posterior wing of the pterygoid. The insertion of this muscle is on 
the angulare and articulare over the entire ventral plate as well as on 
the dorsal face of the median extension of these bones (Plate 6, fig. 19). 
Those muscle fibers that pass around the ventral side of the jaw to an 
extreme lateral insertion have their origin along the surface of the 
tendinous sheath instead of extending to the pterygoid bone. 
The innervation (Plate 3, fig. 6, pt-md.) is from a ventral twig of the 
same ramus of mandibular V which innervates the deeper portion of 
the m. pterygoideus. 
M. pterygo-sphenoidalis posterior (pt-sph. p., Figs. H, I, Plate{6, 
figs. 16, 17) of Bradley. The following is Bradley’s (:03, p. 478) 
3 P % 
