594 Proceedings of the Royal Society of Edinburgh. [Sess- 
Other writers have pointed out that the true inca bone occurs in races 
in which a persistent frontal suture frequently occurs. It is of some interest 
to know that about the same time that I received the New Caledonian 
kanaka skull with the double inca bone, I also received the skull (No. 1027) 
of a Malekula kanaka woman with a well-marked persistent frontal suture. 
Conclusions . — The term “ inca bone ” was used primarily to designate a 
bone corresponding in position and extent with the ununited membranous 
Fig. 6. 
portion of the occipital. It would be well to restrict its application 
accordingly. The “ inca bone ” would thus be distinguished from other 
bones occurring in this region to which the name “ interparietal ” has been 
loosely and sometimes indiscriminately applied. Some adventitious bones 
occurring in the region of the junction of the sagittal and lambdoid sutures 
are simply Wormian bones ; others are doubtful as regards homology, and 
may be Wormian bones modified, in respect of some of their margins, by the 
normal “ embryological sutures.” 
(Issued separately August 29 , 1908 .) 
