134 



PHYLOGENY OF FUSUS AND ITS ALLIES. 



The following table shows these species in their geologic and 

 biologic relations with the probable origins and migrations indicated. 

 The species of ClaveUofusus are also shown. 



Lower Eocene. 



Middle Eocene. 



n 



n 



n 



Upper Lower 



Eocene. Oligocene. 



n 



n 



n 



n 



n n 



n 



n 



ns- n •" 





t~- 



n 



n 



n n 



n 



n 





n 



r^ 



n n 



n 



