R- delete the tail word

Can someone teach me how to delete tail word ,thanks.

from

 1 North Africa                                 
 2 Algeria                                      
 3 Canary Islands (Spain)[153]                  
 4 Ceuta (Spain)[154]

to

 1 North Africa                                 
 2 Algeria                                      
 3 Canary Islands                
 4 Ceuta

I'm sad with my poor English.