352 KANSAS UNIVERSITY SCIENCE BULLETIN. 



Articulations. 



The palatine has two. On the dorsal edge it articulates with 

 the pterygoid, and the anterior part of the inner face with the 

 frontal. The anterior prolongation fits in between the first 

 suborbital and the vomer, but touches neither. 



Maxilla. (Plate XXV, Max.; plate XXXV, figs. 59, 60.) 



The maxilla is a long, slender bone, bearing no teeth and 

 having nothing to do with mastication. Its anterior end is 

 elliptical and the posterior end is very thin. The outer face 

 is convex posteriorly and slightly concave at the anterior end. 

 At about four-fifths of the distance to the posterior end the 

 bone is constricted, and back of this it becomes very thin. At 

 the anterior end the bone is drawn down ventrally and forms 

 a head or condyle, which articulates with the vomer. 



Articulations. 



The maxilla has three articulations. The articulation on the 

 vomer is near the anterior end and the two maxillse touch each 

 other at the anterior end. The articulation with the premaxilla 

 is along the ventral edge. The ventral part of the condyle fits 

 into a small depression on the inner side of the premaxilla. 



Premaxilla. (Plate XXV, Premax.; plate XXVIII, figs. 5, 6.) 



The premaxilla has a good supply of teeth, most of them 

 being canine-shaped. The number is different, but averages 

 8 or 9. The first four or five are large and the rest are small 

 and rounded. The anterior tooth is usually single ; posterior to 

 this the large ones form a double row, and the remaining small 

 ones a single row. 



Outer Face. (Plate XXVIII, fig. 5.) 



The premaxilla is shaped in a peculiar manner. The an- 

 terior part of the bone is heavy and the long axis is placed 

 dorso-ventrally. At the base of the posterior edge there is a 

 projection which points posteriorly. It narrows down back of 

 the teeth and becomes a spine. This projection is at right angles 

 to the rest of the bone. The outer face is convex and is marked 

 by striations. At the base of the two anterior teeth there are 

 two foramina. The dorsal edge is rounded at the expense of 

 the posterior edge. 



The inner face of the premaxilla is rather irregular. The 

 anterior part of the face is smooth and is the symphyseal 

 surface. Posterior to this it is very rough. There is a groove 



