3IO THE EVOLUTION OF MAN. 



VIII. Eighth P^-riod: Skeleton of the Monotremata (Fif?. 19fi, p. 148). 



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

 characterif«tic's of Mammals. 



IX. Niiitli Period : Skeleton of the Marsiipialia (Y'l^. 197, p. 152). 



'I'he cnrficoid bono of the shoulder-girdle becomes atrophied, and thr 

 remnant of it amalgamates wiih the slioulder-blade. 



X. Tenth Period : Skeleton nf the Semi-a-pes: (Fig. 199, |>. 1^4^. 



'•'he i^K'Ucli-bones, which distinguish IMonoiremes and Marsuj ials, 

 disappear. 



XI. Eleventh Period : Skeh-fnv of thp. Anthropoid Apea 

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



The skoleton acfiuires the peculiar development shared by Man ex- 

 clusively with the Anthropoid Apes. 



