Genesis 10:22 sets out the "sons" of Shem as: Elam, and Asshur, and Arpachshad, and Lud, and Aram.
While almost all scholars accept this putative genealogy as a description of the root Semitic cultures known by the Hebrews at the time, there are many, many descriptions of what two of these names mean. Aram, Asshur and Elam are known definitively as the cultures of those respective cities, the Elamites of present-day Southwest Iran, the Assyrians of the upper Tigris river valley, and the Arameans of Northern Syria.
The name Lud is accepted by many scholars to refer to the Lydians of the (now) Manisa region turkey. However, the Lydians were not semitic speakers, but instead spoke an Anatolian language. It is therefore highly unlikely that the Hebrew scholars would have listed them as "sons of Shem" (i.e., Semitic). In fact, Lud more likely represents a corrupted spelling of the city, Lubdi, a city well known from cuneiform script and situated between the upper Tigris river and the Euphrates, north of Babylon.
The last of the five "sons" of Shem is Arpachshad (ARPKSD). This city has been identified by most scholars as the city of Arabkha in modern-day Kirkuk, Iraq. Also, many scholars further identify this city as the infamous Ur-Kasdiym, mentioned in Genesis as the birthplace of Abram's father Terah.