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of the palato-quadrate cartilage. The dorsal edge of the bone overiaps externally and suturates 

 with the ventral edge of the entopterygoid, bounding, in its posterior portion, the short anterior Pro- 

 longation of the palato-cpiadrate cartilage just above described. Its hind edge overiaps both extern- 

 ally and internally and articulates with the anterior edge of the quadrate, in the manner just above 

 described. Near the ventro-posterior end of the free, ventral edge of the bone, there is a flat ridge- 

 like process, the function of which was not evident in my preparations. 



The ENTOPTERYGOID is a relatively large, thin, sub-oval bone, the anterior end of which 

 overiaps internally the palatine, the ventral edge similarly overlapping the dorsal edge of the ecto- 

 pterygoid. Its hind edge is flexibly bound to the anterior edge of the metapterygoid. In a slight 

 depression on its outer surface, at its ventro-posterior corner, it lodges the short anterior Prolongation 

 of the palato-quadrate cartilage. 



The PALATINE is a stout irregulär bone, with a short body, a right-angled rnaxillary process, 

 and a short ventral process the ventral edge of which is broadened and corrugated but bears no teeth. 

 The hind end of the bone suturates with the ectopterygoid and entopterygoid, being overlapped 

 externally by the former bone and internally by the latter. The three bones enclose between them 

 a small palatine remnant of the palato-quadrate cartilage, this cartilage not being exposed on the 

 outer surface of the apparatus. The rnaxillary process of the palatine is a stout process, the proximal 

 portion of which is directed antero-dorso-laterally and the distal portion antero-ventro-mesially, 

 the two parts lying nearly at a right angle to each other. The dorsal surface of the flat distal portion 

 of the process lies against, and has a sliding articulation with the internal surface of the lachrymo- 

 palatine process of the nasal bone, the ventral surface of the process giving articulation to, and being 

 firmly bound by fibrous tissue to, the dorsal surface of the rnaxillary bone. Immediately posterior 

 to the surface of contact with the nasal, the hind end of the flat dorsal surface of the rnaxillary process 

 has a sliding articulation with the two little articular ridges on the internal surface of the dorsal 

 edge of the lachrymal. 



On the internal surface of the base of the rnaxillary process of the palatine, there is a V-shaped 

 groove which has a wide dorsal end and from there tapers gradually downward to a point. This 

 V-shaped groove articulates with the anterior edge of the lateral process of the vomer, and possibly 

 also with adjacent portions of the corresponding edge of the pedicle of the ectethmoid, in the manner 

 already described when describing those bones. Ventral to the groove there is, on the internal 

 surface of the anterior end of the ventral process of the palatine, a concavity which gives insertion 

 to the short vomero-palatine ligament and comes in contact with the lateral surface of the head of 

 the vomer when the palato-quadrate apparatus swings inward. The dorsal edge of the body of the 

 bone, and the dorsal edge of the entopterygoid immediately posterior to it, are both bound by strong 

 tissue to the ventral surface of the pedicle of the ectopterygoid, touching that bone when the palato- 

 quadrate apparatus Swings inward. 



The MANDIBLE contains dentary, articular and angular elements. 



The dentary has the usual V-shaped hind end, the two limbs of the V being of about equal 

 length. The ventral limb tapers gradually to a point, and its hind end lies in a deep groove along 

 the internal surface of the articular. The dorsal limb of the bone is covered with small villiform teeth 

 and ends in a flattened hind end which replaces functionally the dorsal end of a coronoid process, 

 that process of the articular being wanting. On the external surface of the bone there is a deep groove 



