48 



Transactions. — Zoology. 



pelvis in the female is therefore shown to be due in almost 

 equal proportions to a shortening of the iliac bones and to a 

 shallowing of the pelvic cavity. 



The characteristic shallowness of the female pelvis is, 

 however, brought out in a more striking way by taking not 

 the absolute depth, but the index of the pelvic cavity — that 

 is to say, the proportion between the pubo-ischiatic depth and 

 the width as taken at the brim. As shown in the table, the 

 male index exceeds the female by 10-7. 



Professor Turner's two specimens have a depth of 92mm. 

 and 106mm., and scarcely alter the average. Their indices 

 are 84-4 and 86'9. These raise the male average to 83'4. 



The ividth of the i)elvic outlet in the males averages 

 94-lmm. ; in the females, 114-lmm. 



There is very little difference between the sexes as to the 

 depth of the ])uhic symphysis. In the males it averages 

 86-3mm. ; in the females, 85'7mm. 



The obturator foramen is, as usual, wider in the female 

 than the male. The mean male index is 62'7 ; the female, 

 71-7. 



The suhpiLhic angle also shows the customary greater 

 width in the female pelvis, the average angle in the males 

 being 63-8°; in the females, 82-1°. 



The acetabulum is in almost every case smaller in the 

 female than in the male. In fourteen cases its two diameters 

 are equal ; in ten the height slightly exceeds the width. 



Saceum (Maori) . 



Twenty-five sacra were sufficiently perfect to allow me to 

 measure both the length and the breadth. Their measure- 

 ments are summarised in the short table below. The indivi- 

 dual measurements of twenty-four are given with the pelves 

 in Table V. Nine of these are given again with the twenty- 

 fifth, in the table of vertebral columns (Table IV.). 



In eight bones a sixth vertebral element is present. This 

 is the first coccygeal in seven instances, and the fifth lumbar 

 in one. In measuring the length, this additional vertebra is, 

 as already explained, always omitted. 



