The gemara in Menachos 34b learns the number of parshiyos in tefillin in various ways. One is ר"ע אומר אינו צריך טט בכתפי שתים פת באפריקי שתים Rabbi Akiva says: ... four compartments can be derived from "totafot" itself: "tot" in Katfi means two, "pat" in Afriki also means two [and therefore tot...