S PROCEEDINGS OF THE NATIONAL MUSEUM vol. G7 



is similarly displaced, but the other sutures of the occipital are not 

 traceable. Because of the fact that so few of the individual bones 

 of the cranium can be defined, it is impossible to tell whether the 

 lateral shortness of the right mastoid and exoccipital, which also 

 means the lambdoidal crest upon this side, is due entirely to the 

 effect of the cervical muscles involved, or also to that of the tem- 

 poral. In all probability both have contributed to the existing state 

 of affairs. It also seems likely that the right cervical musles pre- 

 viously enumerated were relatively weak. 



The medial portion of the right petrous temporal has been ad- 

 vanced several millimeters, with corresponding displacement of the 

 origins of the palati muscles. The origin of the right internal ptery- 

 goid is larger than the left, but the difference is not of greater 

 degree than occurs in symmetrical skulls. The right curve of the 

 palatal shelf extends slightly farther craniad than the left, indicat- 

 ing a corresponding disparity between the insertions of the two 

 tensor palati muscles. 



An examination of the superior aspect of the skull at once dis- 

 closes the fact that the right temporal fossa as a whole is consider- 

 ably smaller than the left. It is not less deep, to any appreciable 

 extent, but the sagittal crest is displaced toward the right and the 

 right lambdoidal crest is shorter. The fact is disclosed, however, 

 that the anterior part of the right temporal was of greater mass than 

 upon the left. This resulted in the displacement, in both anterior 

 and lateral directions, of the right frontal, now best shown by the 

 position of the supraorbital ridging. The origin of this part of the 

 muscle is thus more extensive upon the right side, and it may well 

 have been thicker also. 



For certain work the right side of the jaw must have been favored 

 to a marked degree. The right condylar articulation was either 

 permanently painful when stressed, which I am inclined to doubt, 

 or what is more likely, theie was some mechanical handicap to its 

 use, such as lesions of the ligaments or condylar capsule, causing the 

 animal to rely largely upon the left side of the jaw. It seems 

 certain that this is the proper explanation for the fact that the pos- 

 terior part of the right temporal muscle was smaller than the left. 

 The fact that the anterior part of the right temporal was larger than 

 the corresponding portion of the left is somewhat unexpected. It 

 would be entirely logical were the temporal muscle divisible into an 

 anterior and a posterior part, but according to Sonntag ^ the division is 

 rather into a superficial and a deep portion. The vacuity of the tem- 

 poral fossa, inclosed by the zygomatic arch, is shorter and broader 

 (transversely) upon the right side, and as the two zygomatic arches 



' Sonntag, C. F., The morphology and evolution of (ho apes and man, London, 1024, pp. 1-364. 



