SB 8.1.27

caturtha uttama-bhrātā
 manur nāmnā ca tāmasaḥ
pṛthuḥ khyātir naraḥ ketur
 ity ādyā daśa tat-sutāḥ
Synonyms: 
caturtha — the fourth Manu; uttama-bhrātā — the brother of Uttama; manuḥ — became the Manu; nāmnā — celebrated by the name; ca — also; tāmasaḥ — Tāmasa; pṛthuḥ — Pṛthu; khyātiḥ — Khyāti; naraḥ — Nara; ketuḥ — Ketu; iti — thus; ādyāḥ — headed by; daśa — ten; tat-sutāḥ — sons of Tāmasa Manu.
Translation: 
The brother of the third Manu, Uttama, was celebrated by the name Tāmasa, and he became the fourth Manu. Tāmasa had ten sons, headed by Pṛthu, Khyāti, Nara and Ketu.