SB 9.15.4
jahnos tu purus tasyatha
balakas catmajo ’jakah
tatah kusah kusasyapi
kusambus tanayo vasuh
kusanabhas ca catvaro
gadhir asit kusambujah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The son of Jahnu was Puru, the son of Puru was Balaka, the son of Balaka was Ajaka, and the son of Ajaka was Kusa. Kusa had four sons, named Kusambu, Tanaya, Vasu and Kusanabha. The son of Kusambu was Gadhi.