Volume VIII 
JANUARY, 1912 
Nos. 3 AND 4 
OBSERVATIONS ON THE OCCIPITAL BONE IN A SERIES 
OF EGYPTIAN SKULLS, WITH ESPECIAL REFERENCE 
TO THE PERSISTENCE OF THE SYNCHONDROSIS 
CONDYLO-SQUAMOSA (ZAALJER ; SYNCHONDROSIS 
INTRAOCCIPITALIS POSTERIOR, BNA.) 
By H. DOROTHY SMITH, B.Sc. Crewdson-Benington Student 
in Craniology. 
While taking a series of measurements at University College, under the 
supervision of Professor Pearson, on a collection of Egyptian crania of the third 
dynasty, the writer noted certain peculiarities in the occipital regions of several 
specimens. In particular a distinct fissure of varying length, extending inwards 
from the masto-occipital suture (the origin being located generally by the mastoid 
foramen) towards the foramen magnum, was well shown in several adult specimens. 
This was identified by Professor Thane with the persistent synchondrosis condylo- 
squamosa described by T. Zaaijer {Anatomisclie Hefte, herausgegeben von F. 
Merkel und R. Bonnet, 1. Abteilung, XII. Heft. 1894<). An examination of the 
collection was then undertaken for comparative purposes, and in this the writer 
is much indebted to both Professor Pearson and Professor Thane for their kind 
assistance. 
The first 1100 specimens examined included the crania of 62 children of whom 
the youngest was probably about 5 years old. The only instance of persistence of 
the synchondrosis condylo-squamosa in its whole extent from the masto-occipital 
suture to the margin of the foramen magnum was found in the cranium of a child 
of about 7 years of age — and this on the left side only, while on the right the 
synchondrosis persists to within 8 mm. of the margin of the foramen magnum. 
In Plate I. will be seen the condition of this cranium with the component parts 
in situ (A) ; in figure (C) will be seen the skull with pars basilaris and pars 
condyloidea removed and these parts are seen separately in Fig. (B). 
The best examples among the adult specimens show an irregular fissure 
(Plates II. and III.), directed transversely inwards from the masto-occipital suture 
for about 25 mm. Of crania showing a fissure of 15 mm, or more in length, 
Biometrika vm 33 
