ix.] OF THE DOG. 143 



jaw moves on the skull. The upper border, between the 

 condyle and the hindermost tooth, rises into a high, com- 

 pressed, recurved process (the coronoid process, cp\ to which 

 the temporal muscle is attached. The outer surface of this 

 process gradually subsides into a considerable hollow in the 

 side of the ramus, with prominent anterior, inferior, and 

 posterior edges, to which the masseter, another powerful 

 muscle for closing the jaw, is attached. 



The point at which the vertical hinder edge of the ramus, 

 descending from the condyle, meets the horizontal inferior 

 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 dental 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. 



The hyoidean apparatus (Fig. 50) consists of a median 

 portion below, the basihyal (b/i), from which two pairs 

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

 The anterior (ch to s/i) is the largest, and connects it with 

 the cranium. The posterior (fh) 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, 

 and by its upper end firmly ankylosed with the surround- 

 ing bones. It can be seen much more distinctly in 

 some dogs' skulls than others, and is more conspicuously 



