MAMMALIA 



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Balaena mysticetus, is a polar inhabitant, each of which yields about 

 3,000 pounds of whalebone and 300 barrels of oil. The finback and 

 humpback whales also belong to this order. In feeding, all of these 

 whales take large quantities of water into the mouth, pass it out 

 through the whalebone which serves as a sieve, and retain all of the 

 small organisms and particles of organic matter as food. 



Order Primates. — This is the order which includes the lemurs, 

 monkeys, apes, and man. Because of the large number of primitive 

 characteristics of representatives of this order, some authors place it 

 near the first or middle of the list of orders of mammals instead of 

 at the end. Most of them are tropical, arboreal, and live on nuts, 

 seeds, fruits, insects, and birds. They have a particularly well- 

 developed brain. The thumb and also the great toe in most forms are 

 placed in opposition to the other digits as an adaptation for grasping. 

 Usually only one young is born in a fairly advanced stage, but rather 

 helpless at first and requiring considerable care. The order is usually 

 divided into two suborders, the Lemuroidea and Anthropoidea. The 

 first includes the lemuroids which have the front teeth separated. 

 These are typically small or medium-sized quadrupeds of Madagas- 

 car, with long, bushy tails. The aye-aye is a nocturnal arboreal ani- 

 mal with long ears, large ratlike teeth, bushy tail, and long digits 

 with sharp claws. Its body is about one foot long. The tarsiers are 

 about the size of rats with suckerlike discs on the ends of their fingers 

 and toes. They are also arboreal and nocturnal. The true lemurs 

 have an elongate face and a small cranium. Their hindlimbs are 

 longer than the forelimbs. Most of them live on Madagascar and 

 nearby islands as well as in Africa and Asia. 



The second suborder, Anthropoidea, includes several families of 

 monkeys and apes. 



The marmosets make up another family found in South and Cen- 

 tral America. They have a flat nail on the big toe, while the thumb 

 is not opposable to the other digits. The brain case is large, and the 

 space between the nostrils is broad. The Cehidae, or New "World 

 monkeys, have long prehensile tails, broad flat noses, and all digits 

 have nails instead of claws. This group includes the common monkey 

 of hand-organ fame, the spider monkeys, squirrel monkeys, and 

 howlers, all of which are natives of Central America and the northern 

 part of South America. 



