220 Variation and Correlation of the Human Skull 
these 24 skulls were compared with the means for the whole series with the follow- 
ing results : 
Character 
Male Skdll 
Female Skull 
General 
Metopic 
General 
Metopic 
Maxiiiuun Breadth 
Least Forehead Breadth 
141 
!}8 
142 
_ 100 
135 
.3 
135 
96 
It would thus seem that a persistent frontal suture may allow of a two to three 
millimetres increase in the minimum forehead breadth, but probably does not 
influence the maximum cranial breadth. 
We may perhaps note here that a metopic fontanelle occurred in one case, the 
male skull, W. 141. 
Traces of a transverse-occipital suture were found in 3 cases and of an infra- 
orbital suture on the face in 2 cases, all males. In 1 female skull there was a 
division of the left parietal bone by a sinuous suture (W. 216), and in 3 cases, 1 male 
and 2 female, the apex of the occipital squama was produced upwards. Frontal 
process of temporal, single or bilateral, was noticed in 4 cases, 2 male and 2 female 
(see Plate XLVI) and a par-occipital process in 1 male skull (W. 192). 
(iv) Interparietals. 
As in the Esquimaux, the English skulls provide in both series a very con- 
siderable number of interparietals, in the Whitechapel series we have 5 male and 
4 female. We may divide them into the simple interparietal, Plate XXXV, and 
the tripartite interparietal, Plate XXXVI. Skull W. 7096 is a good example of this 
although it is not as clearly shown in the plate as one might have wished. The 
complete tripartite interparietal consists as in skull W. 7096 of three parts. First 
the pentagonal shajjed centre bone and then two triangular wings. These have been 
termed by Professor Thane the os 'pentagonale and the ossa triangularia respec- 
tively. Almost every form of this tripartite interparietal occurs in this English 
series. Thus we may have ; (i) all three parts free as in Plate XXXVI. (ii) The 
05 pentagonale fused and the ossa triangularia separate as in Plate XXXVII. 
(iii) The os pentagonale separate and the ossa triangularia fused as in Plate XL. 
(iv) The OS pentagonale separate and the left os triangulare only separate, the right 
fused as in Plate XXXIX, or (v) the os pentagonale separate and the right os 
triangulare only separate, the left fused as in Plate XXXVIII. Cases of one os 
triangulare separate, and the other as well as the os pentagonale fused did not occur 
in this series. Still the series is so comprehensive and interesting that it seemed 
worth while to figure these interparietals fully, so that they may serve as standards 
for reference in other cases. 
Taken as a whole the series appears to possess very considerable interest from 
the standpoint of special or "abnormal variations." The fact that the same high 
