.588 Proceedings of the Royal Society of Edinburgh. [Sess. 
The persistence of the separation of the upper part of the supraoccipital 
and of the lower part of the malar are examples of the latter, and are not 
Wormian bones.” 
In view of these different statements, one naturally wishes to have some 
evidence regarding the particular structure to which the name inca bone 
was originally applied. I think I can supply this, even if the information 
is somewhat second-hand. Some time ago I became possessed of a copy of 
Lieut.-Colonel Charles Hamilton Smith’s work on The Natural History of 
the Human Species (Edinburgh, W. H. Lizars, 3 St James’ Square, 1848). 
In it (on plate i.) there are two small lithographs of the skull of a Taticaca 
child. The occipital view shows a large undivided inca bone, posterior to 
the lambdoid suture. In the text (p. 145) Colonel Hamilton Smith says : 
“ Dr Tschudi, describing this form, in his paper on the ancient Peruvians, 
remarks on the flattened occiput of the cranium, and observes, ‘ that there 
is found, in children, a bone between the two parietals, below the lambdoidal 
suture, separating the latter from the inferior margin of the squamous part 
of the afterhead ; this bone is of a triangular shape, the upper angle between 
the ossa parietalia, and its horizontal diameter, being twice that of the 
vertical. This bone coalesces at very different periods with the occipital 
bones, sometimes not till after six or seven years. In one child of the last- 
mentioned age, having a very flat occiput, the line of separation was marked 
by a most perfect suture from the squamous part, and was four inches in 
breadth by two in height.’ In remembrance of the nation where this 
conformation is alone found, the learned doctor denominated this bone Os 
Incce ; and he further remarks, that it corresponds to the Os interparietalis 
of Rodentia and Marsupiata.” 
Perhaps the homology in Tschudi’s description halts a little, like the 
Latinity. But it is clear from the quotation that the inca bone of Tschudi 
bore little if any resemblance to the bone in the Helvetian skull figured by 
Vogt and described by him as a “ well-developed os incse.” It appears to me 
that the round bone in the Helvetian skull is nothing else than a Wormian 
bone in a somewhat unusual position, viz., in the sagittal suture. And yet 
the position may be found on investigation not to be so very unusual, seeing 
that Wormian bones occur in every suture. I have seen a large triangular 
bone in the position of the anterior fontanelle of an Australian aboriginal. 
Had this os antiepileptium occurred in a similar condition at the posterior 
extremity of the sagittal suture, it might have been called by some an inca 
bone or an interparietal 
The “ separate interparietal ” figured by Morris and referred to in Quain, 
is a bone that belongs undoubtedly to a different category. It is the inca 
