IX.] OF THE DOG. 123 



border, is called the angle, which in the Dog is prolonged 

 into a conspicuous compressed process, with an upturned and 

 slightly inverted pointed extremity, the angular process (a). 

 On the inner side of the ramus, a little way in front of and 

 below the condyle, is the inferior dcJital foramen {id), for the 

 admission of the inferior dental nerve (from the fifth pair) 

 and artery. On the outer side of the ramus, near its anterior 

 extremity, is the mental foramen, through which a branch of 

 the same nerve passes out to the lower lip and surrounding 

 structures. 



Fig. 48. — Extracranial portion of hyoidean apparatus of Dog, front view, sh stylo- 

 hyal ; eh epihyal ; ch ceratohyal (these three constitute the "anterior cornu ") : 

 bh basihyal, or " body" of hyoid ; th thyrohyal, or "posterior cornu." 



The hyoidean apparatus (Fig. 48) consists of a median 

 portion below, the basihyal (bh), from which two pairs 

 of half arches, or " cornua," extend upwards and outwards. 

 The anterior {ch to sh) is the largest, and connects it with 

 the cranium. The posterior {th) is united externally or 

 superiorly with the thyroid cartilage of the larynx. In the 

 Dog there are four distinct ossifications in the anterior arch. 

 The first is a small cylindrical piece of bone lying in a 

 canal between the tympanic and periotic bones, immediately 

 to the inner and anterior side of the stylomastoid foramen. 



