So here is a question that I hope won't prove intractable. There are in biological classification in the Class Mammals two subclasses: Prototheria and Theria. The second includes 25 Orders and 1,000s of species. The first includes only one Order [Monotremata] and that contains two species of one mammal and one species of another. Name (the common name) the two members of Monotremata and where both are located in the world. Don't get hung up in the scientific names, it is easy really with a little knowledge of the unusual life in the world.