ed nostrilled or Amphirrhma 

 itk Amnion, vrithout gills. 



PI. in'. 



IMALS 



'SI 



Eelative lengths of the 5 

 Epochs in per centages. 



Quartemaiy Epoch 0.5 



Tertiarj EpocTi 2 . 3 



Secondary Upocli 11. 5 



Primary Epoch 32. 1 



IHmordial Epoc h 53-6 

 Total 100.0 



il 



