314 ZOOLOGY 



tions for food getting and escape from enemies, the seasonal 

 change in color of the weasel is an example of an adaptation 

 which serves both of the above purposes. This is only one of 

 hundreds of others that might be mentioned. 



The California sea lion {Zalophus calif ornianus). Photographed in the Philadelphia 



Zoological Gardens by Davison. 



Economic Importance. — The Carnivora as a group are of much 

 economic importance as the source of most of our fur. The fur 

 seal fisheries alone amount to millions of dollars annually. Otters, 

 skunks, sables, weasels, and minks are of considerable importance 

 as fur products. In India tigers do considerable harm in some 

 localities, and in our own country wolves, pumas, and wild, cats do 

 some damage. 



Ungulates: Hoofed Mammals. — This group includes the domesti- 

 cated animals as the horse, cow, sheejD, and pig. A group of ani- 

 mals which originally roamed wild, they eventually came under 

 the subjugating influence of man. Now they form a source of 

 the world's wealth, and are an important part of the wealth 

 of the United States. 



The order of ungulates is a very large one. It is characterized 

 by the fact that the nails have grown down to become thickened 

 as hoofs. In some cases only two (the third and fourth) toes 

 are largely developed. Such animals have a cleft hoof, as in the 

 ox, deer, sheep, and pigs. These form the even-toed ungulates. 



