$ sudo apt-get update
$ sudo apt-get install libgeography-countries-perl 

libgeography-countries-perl is installed in your system.

Make ensure the libgeography-countries-perl package were installed using the commands given below,

$ sudo dpkg-query -l | grep libgeography-countries-perl *

You will get with libgeography-countries-perl package name, version, architecture and description in a table

libgeography-countries-perl package basic information: