252 



DISCOVERY REPORTS 



FEMALE SKULLS 



(Plates VIII, IX and X) 



The identifiable female skulls are thirty-two in number, and like those of the males 

 display four age groups. 



On the whole the female displays rather greater individual variation than the male. 



First year (3). Body length 232-3 cm.; skull length 332 mm.; zygomatic width 

 174 mm.; alveolar length 89-8 mm. At this stage the skulls closely resemble those of 



420 



400 



380- 



c 



QJ 





360 



340 



320 



Years of Ag"e 

 Fig- 3. 



1/ Averages of Age Groups 

 Skull Length 



<5_ 9- — 



I 



n I m 



Years of Ag"e 

 Fig- 4- 



]¥ 



Fig. 3. Graphical representation of growth stages of body, both sexes. 

 Fig. 4. Graphical representation of growth stages of skull, both sexes. 



the males and exhibit the rounded form, comparatively poor ossification and conspicuous 

 sutures of the immature animal. The vertical plates of the pterygoids are frequently 

 inclined outwards — a juvenile character which is found in the male skull throughout 

 life — and the occipito-sphenoidal suture may begin to fuse. Cheek teeth crowded. 



Second year (11). Body length (5) 279-3 cm.; skull length 387-7 mm. ; zygomatic 

 width 199-3 mm.; alveolar length 101-5 mm. The bone is denser, the coronal and 

 squamosal sutures are almost entirely fused, the occipito-sphenoidal is usually fused and 

 may be obliterated, and the alveolar length has increased. 



