THE MAMMALS 457 



that possessed by man, yet his biceps is smaller in size. It is only by 

 our superior intelligence that we are able to survive in a world where 

 competition is so keen. 



Classification and Derivation of Scientific Words 



Phylum Chordata (Cont.) 



Class G. Mammalia (L. mamma, breast; nourish their young by 



means of mammary glands on the breast). 

 Order 1. Monotremata (L. monos, one ; trcma, hole ; have only one 



posterior opening of the body, or a cloaca). The duckbill. 

 Order 2. Marsupialia (L. marsupium, pouch; have a pouch in 



which they carry their young). The opossum and kangaroo. 

 Order 3. Insectivora (L. inscctum, an insect; vorarc, devour; 



insect-eating animals). Mole, shrew, hedgehog. 

 Order 4. Chiroptera (Gr. cheir, hand; pteron, wing; the hand has 



been modified to form a wing). The bats. 

 Order 5. Carnivora (L. carnis, flesh; vorarc, devour; flesh-eating 



mammals). The cats, dogs, hyenas, raccoons, civet cats, skunks, 



bears, seals, sea lions, and walruses. 

 Order 6. Ungulata (L. ungula, hoof; bear hooves on their feet). 



Horses, tapirs, rhinoceroses, pigs, peccaries, hippopotami, cattle, 



deer, antelopes, goats, sheep, giraffes, camels, and llamas. 

 Order 7. Cetaceae (L. cetus, whale). The whales and porpoises. 

 Order 8. Proboscidea (Gr. pro, before; boscein, feed; bear a long 



proboscis on the front of the head used in feeding). Elephants. 

 Order 9. Sirenia (Gr. siren, a mermaid; members of this order 



bear little resemblance to the mermaids). The sea cows. 

 Order 10. Rodentia (L. rodare, to gnaw; these are gnawing mam- 

 mals). The squirrels, rats, porcupines, etc. 

 Order 11. Lagomorpha (Gr. lagos, a hare; morphe, form). The 



rabbits and hares. 

 Order 12. Edentata (L. e, without; dentis, tooth; these are the 



so-called toothless mammals, although some of them have small 



jaw teeth). The armadillos, sloths, and ant bears. 

 Order 13. Primata (L. primatis, first; so named because this is 



considered to be the first of the animal groups in importance). 



The lemurs, monkeys, apes, and man. 



REVIEW QUESTIONS 



1. Give the characteristics of the mammals. 



2. What is meant by a cloaca and what is its relation to the mammals? 



