#Since Rails doesn't load classes unless it needs them, you must read the models from the folder. Here is the code
    Dir[Rails.root.to_s + '/app/models/**/*.rb'].each do |file| 
      begin
        require file
      rescue
      end
    end

    models = ActiveRecord::Base.subclasses.collect { |type| type.name }.sort

    models.each do |model|
      print model
      print '  '
    end