DR. J. THUENAM ON SYNOSTOSIS OF THE CRANIAL BONES. 249 



tlie klinoid form of this skull, wliicli, according to the ordinary- 

 view, ought rather to have been scaphoid, may depend upon the 

 activity of the growth of the middle lobes of the brain, in the 

 direction outwards, or of the parietal tubers ; whilst in scaphoce- 

 phalus, the compensatory cerebral growth is forwards and back- 

 wards, in the axis of the anterior and posterior lobes. This view is 

 confirmed by observing that in many cases of the second, or sub- 

 scaphoid form of synostotic dolichocephalus, there is a considerable 

 saddle-shaped contraction in the coronal and temporal regions ; 

 though not enough to constitute klinocephalus, as usually under- 

 stood. In this way, a sort of gradation is to be noted between 

 scaphocephalus and klinocephalus, depending on synostosis of the 

 parietals. In both the cases of the first of these deformities in an- 

 cient British skulls from Long Barrows, which are figured and 

 described in this paper, a certain tendency to klinocephalism is to 

 be observed. 



Fig. 3. Vertical view of the Alinocephalic Skull of a Gentoo oMld. — 

 Quarter Diameter. 



In the Table of Measurements appended hereto, I give all the 

 examples of abnormal synostosis of the parietals which I have had 



are no doubt due to the synostosis of the apex of the occipital with the biparietal. 

 A tendency to kUnocephahsm is especially observable in the skulls of Kanakas, 

 when affected by synostosis of the paiietals. In the large series of about 135 Ka- 

 naka skulls in the Barnard-Davis collection, there are six instances of this form of 

 SATiostosis, only one of which is sub-scaphocephalous, whilst in the others a greater 

 or less degree of saddle-shaped contraction, and in one complete klinocephalism, 

 is to be observed. Measurements of these skulls are given in the Table. With 

 other synostotic skulls in this rich collection they are described by Dr. Davis in a 

 niemoh- now being printed in the Transactions of the Society of Sciences of Haarlem. 

 My attention was more especially drawn to this subject by tlie opportunity afforded 

 me of perusing part of this memoir whilst in manuscript more than two years ago. 

 N.H.R. — 1805. S 



