Dr de Tschudi on the Ancient Peruvians, 253 



years. In one skull belonging to a child about seven years 

 old, with a very flat occiput, this line is separated by the most 

 perfect suture from the squamous part of the occiput, and is 

 4 inches broad and 2 inches high. In a more advanced age, 

 it probably completely integrates with the rest of the skull. 

 I have, however, perceived it in all the skulls of this class 

 which I have examined. On a close scrutiny, we generally 

 find traces of it in the linea semicircularis superior. 



This bone, which, in remembrance of the nation in which it 

 is found, I call Os Incce^ corresponds entirely to the Os inter- 

 parietalia of the Rodentia and Marsupialia. We know that it 

 exists in these classes of mammalia through life — that it also 

 occurs in the foetal state of several pachydermata, ruminantia, 

 carnivora, &c. In the ordinary embryos of man, there are 

 barely some traces in the first months, which, however, soon 

 disappear. I think it, therefore, very curious that we should 

 find so retarded a formation in a whole race of men, who have 

 exhibited a very inferior degree of the intellectual faculties. 



I have just heard that Mr Bellamy, in a paper on Peruvian 

 Mummies, read before the British Association on the 3d of 

 August 1841, and printed in the Annals and Magazine of Na- 

 tural History, October 1842, has already pointed out this pe- 

 culiarity in the osseous structure, and I am much pleased to 

 confirm his observations by the examination of more than a 

 hundred of such skulls. 



I may, however, observe, that Mr Bellamy certainly did not 

 obtain his mummy from the high plams of Peru, as in those 

 districts there occurs no drift sand strongly impregnated with 

 salt. In those plains the mummies are not found in any 

 quantity at a short distance below the surface ; and, lastly, 

 Captain Banckley, who could obtain any quantity of mummies 

 at Arica, or some other seaport town, would certainly not have 

 taken the trouble of fetching them from the high plains. Dr 

 Bellamy is also too hasty in determining the race of the na- 

 tion to which these skulls belonged, especially if he ascribe 

 them to that nation, which is said to descend from Asiatics, 

 who emigrated with Manco Capac. 



I transmit to the Society the drawing of a skull, which I 

 dug out of the old Indian fortification Thrickay. It belongs 



