Belonging to the Gershonites: Ladan and Shimei.
References for 1 Chronicles 23:7
The sons of Ladan: Jehiel the first, Zetham and Joel—three in all.
The sons of Shimei: Shelomoth, Haziel and Haran—three in all. These were the heads of the families of Ladan.
And the sons of Shimei: Jahath, Ziza, Jeush and Beriah. These were the sons of Shimei—four in all.
References for 1 Chronicles 23:10
Jahath was the first and Ziza the second, but Jeush and Beriah did not have many sons; so they were counted as one family with one assignment.