364 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



articulated with the postfrontal. Its connection must have been with 

 the border of the parietal. The epipterygoid of the left side has its 

 upper end missing (fig. 2, numeral 8). On the right side this bone is 

 uninjured. Its upper end is moved well outward toward the post- 

 frontal, but it is probably joined to the parietal. The suture between 

 the latter bone and the postfrontal is obscure. Just behind the base 

 of the epipterygoid the width of the pterygoid is 64 mm. 



The inner and anterior end of the transverse bone (figs. 1, 2, nu- 

 meral 36) overlaps the outer border of the pterygoid, as if it had 

 been pressed somewhat out of its natural relations; but in both 

 Sphenodon and Cyclum the transverse bone overlaps the pterygoid. 

 From the outer border of the pterygoid and of the transverse bones 

 a strong process, 29, descends to a point a little below the upper 

 border of the lower jaw. Marsh indicates that this process belonged 

 wholly to the transverse, but the suture between the two bones is dis- 

 tinct. The transverse measures 160mm. from its inner end to the 

 extremity of the process mentioned. Just in front of the inner end 

 of the transverse the pterygoid is 15 mm. wide. 



The sutures separating the pterygoid, the palatine, and the vomer 

 are not as distinct as could be desired. Nevertheless their courses 

 may be made out more or less satisfactorily. The bones of the right 

 and left sides did not articulate on the midline. Doubtless there 

 was, at least posteriorly, a considerable interval between them. In 

 the skull, as preserved, the rounded inner, or upper, border of the 

 bones of the right side rise several millimeters above those of the 

 left side. 



Mostly hidden by the lachrymal and the jugal, in a side view of the 

 skull, is a considerable vacuity in the bones of the roof of the mouth. 

 Its fore and aft extent is 90 mm. This is called by Lambe the sub- 

 orbital vacuity. It seems to correspond to the postpalatine foramen 

 of lizards, turtles, and sphenodon. It is bounded behind by the trans- 

 verse and mesially, in part, by the pterygoid. In fig. 2 the vacuity 

 is mostly hidden by the lachrymal. A part of it, with light shading, 

 appears between the two numerals 20; the hinder part is shaded 

 dark and is in front of numeral 36. 



Another fissure in the roof of the mouth is seen through the antor- 

 bital vacuity and is situated just above the border of the maxilla. 

 This is the internal nasal passage (fig. 2, numeral 16). It extends 

 forward to the anterior end of the antorbital vacuity and backward 

 to a bar of bone that bounds the postpalatine vacuity in front. The 

 whole extent of the internal nasal passage, as seen, is 85 mm. Pos- 

 sibly it extended forward sonic distance beyond the front of the antor- 

 bital vacuity. 



The bone that lies between the postpalatine vacuity and the nasal 

 passage is undoubtedly the palatine (figs. 1, 2, numeral 20). A 



