Something like this?

package Base;
our %types = qw/BASE_TYPE Some::Class/;

sub get_type {
    return %types;
}

package Foo;
our @ISA = qw/Base/;
our %types = qw/FOO_TYPE Another::Class/;

sub get_type {
    return ( Foo->SUPER::get_type(), %types );
}

package Bar;
our @ISA = qw/Base/;
our %types = qw/BAR_TYPE Yet::Another::Class/;

sub get_type {
    return ( Bar->SUPER::get_type(), %types );
}

package main;
use Data::Dump qw[ pp ];

my %foo_type = Foo->get_type();

pp \%foo_type;

my %bar_type = Bar->get_type();

pp \%bar_type;

__END__
c:\test>junk3
{ BASE_TYPE => "Some::Class", FOO_TYPE => "Another::Class" }
{ BAR_TYPE => "Yet::Another::Class", BASE_TYPE => "Some::Class" }
[download]