Ocean Life 167 
external ears and their hind limbs are of little use except 
for swimming. Eared seals, which include sea lions and fur 
seals, have small but well developed ears and move about 
on land. with more ease than the true seals because their 
hind limbs have greater independence and mobility. 
Sea lion rookery on St. George Island (habitat group). 
The largest sea lions inhabit the North Pacific and reach 
a length of about twelve feet. Those native to the Pacific 
coast of South America are smaller and have a slight mane 
formed by lengthened hair on the neck. Still smaller are the 
California sea lions. 
Fur seals were hunted for their valuable fur until they 
were nearly exterminated. Their breeding places, called 
rookeries, are now protected to some extent under inter- 
