224 THE ANTARCTIC MANUAL. 
smallest skull of the eight known. All things considered, it is evi- 
dent that there can be no striking differences between the sexes of 
this seal, and it is as likely as not that differences of size represent 
age and not sex. 
Dentition.— Undoubtedly a great deal of the interest aroused by 
Ommatophoca centres in its dentition, owing to the remarkable varia- 
tions shown by the different skulls as yet examined. On this account 
it is hoped that as large a number of skulls as possible will be obtained 
by the present Expedition, and that especial care will be given to their 
sexing. No number of sexed skulls, of whatever age, can be too great 
to be of value, for the present is a particularly important animal to 
students of variation, and for the proper study of its eccentricities in 
dentition very large series are required. 
