218 Mammalia. 



sible, for the mastoid process of Anthropotomy is here 

 represented by a small separate stunted bone intervening 

 between the paroccipital process (external jugular of occipital 

 in Man), and the post-tympanic process of the squamosal. 



And here it may be noted as a general statement that all 

 the muscles attached in Man to the Mastoid process, in this 

 animal are attached to the paroccipital process instead. 



The small muscle running across, and external to the 

 posterior belly of the Digastric, will be traced back to arise 

 from a moveable bony head just internal to the point of the 

 paroccipital process ; this moveable ossicle is the end of the 

 styloid bone (a process of the tympanic in man) : forward it 

 will be traced internal to the Submaxillary gland and duct ; 

 and by reflecting forwards the gland substance posterior to the 

 duct (carefully leaving the duct and nerve plexus in situ) this 

 muscle may be seen to be inserted into a moveable ossicle, in 

 the middle line between the rami, and a little anterior to the 

 angle of the jaws, the ossicle being a portion of the Hyoid 

 bone. This muscle is therefore known as the Stylo- Hyoid ; 

 and its action is to draw back and elevate the os hyoides. 



Internal to the Stylo- Hyoid Muscle is a large nerve trunk 

 winding from within the Paroccipital process, in a course 

 almost parallel with the posterior margin of the jaw. This is 

 the ITyjwglossal Nerve^ the motor nerve of the tongue. This 

 will be traced back later on, when examining the back, or 

 base of the skull. 



Removal of Lower Jaw. The Student will now clean 

 away and reflect upwards from the surface of the Masseter 

 muscle the Parotid gland, and nerves ramifying therein ; 

 and then take a saw and make the three following cuts, only 

 partially severing the bone, and completing the fracture by 

 working a chisel in the groove, so as to avoid injuring the 

 structures immediately internal to the bone by cutting too 

 deepwith the saw, viz. : 1, from the angle of the mouth 



