324 Piof. D. M. S. Watson oti 



Separated from the process of the prootic above described 

 by a V-shaped notch is another u[)standing' process, which 

 rises irom tlie outer surface of the body of the bone, so as to 

 leave a notch wliich continues tlie middle groove on the 

 sphenoid and gives exit to tiie facialis. 



This process touches, and in adults fuses with, a slender 

 descending process from the parietal, the bar so formed being 

 sepal ated from the hinder border of the upper part of the 

 sphenoid by a slit. 



Three other bones occur in the neural cranium of old 

 individuals. The mutual relations of these elements is clear, 

 but their exact position in the skull cannot be determined. 



One of these bones is bilaterally symmetrical, andean only 

 be a su[)raoccipita!. It is known to me only from thevisceral 

 surface in one very large skull. 



It is a small h xagonal bone, lightly ossified, but of con- 

 siderable thickness. The dorsal surface has a considerable 

 extension, the smooth endocranial surface being very small. 

 It was undoubtedly separated from all other bones by a great 

 deal of residual cartilage. 



The posterior of the two remaining pairs of bones is the 

 first of the series to ossify. 



It consists of an almost square, vertically placed sheet of 

 bone with a flat admesial surface. The upper margin of this 

 sheet is turned outward, so that it lies horizontally. The 

 posterior lateral corner of this region projects as a definite 

 process of comparatively small antero-posterior width. 



The vertical part of this bone is pierced near its hinder 

 margin by two small foramina, the anterior and laiger of 

 which lies at the upper end of a deep well-defined groove. 



The third element is attached to the lower two-thirds of 

 the anterior margin of the vertical part of that just described. 

 It also is a mere sheet of bone standing vertically, but is 

 placed nearly transversely in the skull. The inner border 

 is smoothly rounded and cut out into a wide shallow bay 

 round the brain-cavity. 



From the middle point of the upper edge of the inner 

 surface of this bone a special very thin bony spicule arises 

 and runs directly foiwaid parallel to the middle line. 



Palato-quadrate. — Two ossifications occur in the palato- 

 quadrate cartilage — a quadrate and the bone called hyoman- 

 dibular by most authors, which has been correctly determined 

 by 8tensio as a metapterygoid. 



The quadrate is a deep slender bone, a large part of whose 

 inner surface is covered by the pterygoid, tlie two bones 



