CHORD ATA — VERTEBRATA — MAMMALS 40 1 



14. Define the order Ungulata. Distinguish them from 

 Unguiculata. 



15. In what part of the Tertiary were the hoofed and clawed 

 mammals very similar in appearance ? 



16. What were the primitive Ungulata like ? The incoming of 

 what food aided largely in their separation into browsing and 

 grazing types ? 



17. Enumerate the ten sub-orders of ungulates with an ex- 

 ample and the geologic range of each. 



18. Give briefly the evolution of the elephant. Distinguish 

 between archaic and modern characters. 



19. Describe the most conspicuous species of elephant in 

 North America during the Upper Tertiary and Pleistocene. 



20. How is the migration of animals brought about ? How 

 does the present distribution of a form give us knowledge of 

 former geographic conditions ? 



21. Distinguish between the tooth of a true elephant (Elephas) 

 and that of the more primitive mastodon. 



22. What sub-order of ungulates in South America paralleled 

 the horses in their development ? In what respects ? 



23. What is the significance of the name Perissodactyla ? 

 Why applied to this sub-order ? 



24. Briefly trace the evolution of the horse. Upon what con- 

 tinent did this probably occur ? 



25. Make sketch to show why the horse's tooth (also ele- 

 phant's tooth) is so well adapted to grinding hard grasses. 



26. What genus of Perissodactyla was one of the largest of 

 ungulates ? 



27. What is the significance of the name Artiodactyla ? 

 Why applied to this sub-order ? 



28. What are the least modified descendants of the Artio- 

 dactyla ? Why ? 



29. Why is it thought that the Lower Tertiary representatives 

 of this sub-order did not chew the cud ? 



30. Distinguish between the molar teeth of the horse and 

 those of a ruminant like the cow. 



31. What difference between solid-horned and hollow-horned 

 ruminants ? Examples of each. When were these groups 

 probably united ? 



32. When and upon what continent did the evolution of the 

 camels take place? 



33. What are sea cows ? Their probable origin ? 



