LIFE. 571 



these later movements. Those conditions and special surface-de- 

 tails were developed that were most essential to the pastoral, agri- 

 cultural, and intellectual pursuits which were to commence with 

 the next age. 



3. Life. — Grand characteristic of the Cenozoic. — The prominent fact 

 in the life of Cenozoic time is the expansion and culmination of the 

 type of Mammals. This culmination took place in the Post-ter- 

 tiary period, whose Carnivores, Herbivores, Edentates, and Marsu- 

 pials far exceeded in number and size those of the present age. It 

 was the great feature not of one continent alone, but of all the con- 

 tinents, and on each under its own peculiar type of Mammalian 

 life. The age of Mammals thus stands out prominently among 

 the ages, strongly marked in its grand distinguishing charac- 

 teristic. 



The Cenozoic was also the time of culmination of the modern 

 tribe of Sharks or Squalodonts, and of the Crocodiles and Turtles 

 among Eeptiles. 



• Range of Vertebrate tyjies. — The following table presents to the eye 

 the range of the more common Vertebrate types through the Me- 

 sozoic and Cenozoic, showing those which began in the Palaeozoic, 

 those which have their commencement, culmination, and end 

 within these eras, and those which continue into the age of 

 Man. The widths of the columns for the several periods cor- 

 respond to the time-ratios as deduced on pp. 493, 568. But 

 they are relatively larger than in the table for the Palaeozoic on 

 p. 400 (2|ds larger), — the column for the Mesozoic being two-thirds 

 as wide as that for the Palaeozoic, when the time-ratios deduced 

 would require it to be one-fourth. This enlargement was given 

 the columns to render the details more distinct. The symbol ) ( 

 signifies having biconcave vertebrae. Under Tertiary, the letters 

 E., M., P., stand for Eocene, Miocene, Pliocene; and P. T. for Post- 

 tertiary. 



While the genera Bos, Bison, and others of the Ox group proba- 

 bly commenced in the Pliocene, the Antelope group first appeared 

 in the early Miocene. Among Carnivores, the Bear family com- 

 menced in the earliest Eocene; the Dog family in the middle 

 Eocene, or Parisian group; the Cat family (Felis, etc.) in the 

 later Eocene, though possibly in the middle. 



In the table the interrogation-mark opposite Herbivores, in the 

 column of the Jurassic period, is inserted on the authority of Owen, 

 who questions whether the Stereognathus of the Purbeck beds (p. 

 462) may not be a " diminutive Ungulate." 



