Numbers 26:57, 58

These were the Levites who were counted by their clans: through Gershon, the Gershonite clan; through Kohath, the Kohathite clan; through Merari, the Merarite clan.

These also were Levite clans: the Libnite clan, the Hebronite clan, the Mahlite clan, the Mushite clan, the Korahite clan. (Kohath was the forefather of Amram