310 THE EVOLUTION OF MAN. 



VIII. Eighth Period: Skeleton of the Monotremata (Fig. 196, p. 148). 



The vertebral column, skull, jaws, and limbs, acquire the definite 

 characteristics of Mammals. 



IX. Ninth Period : Skeleton of the Marsupialia (Fig. 197, p. 152). 



The coracoid bone of the shoulder. girdle becomes atrophied, and the 

 remnant of it amalgamates with the shoulder-blade. 



X. Tenth Period : Skeleton of the Semi-apes (Fig. 199, p. 164). 



The pouch-bones, which distinguish Monotremes and Marsupials, 

 disappear. 



XI. Eleventh Period : Skeleton of the Anthropoid Apes 

 (Figs. 204-208, p. 179). 



The skeleton acquires the peculiar development shared by Man ex- 

 clusively with the Anthropoid Apes. 



