SB 6.18.5

vālmīkiś ca mahā-yogī
 valmīkād abhavat kila
agastyaś ca vasiṣṭhaś ca
 mitrā-varuṇayor ṛṣī
Synonyms: 
vālmīkiḥ — Vālmīki; ca — and; mahā-yogī — the great mystic; valmīkāt — from an anthill; abhavat — took birth; kila — indeed; agastyaḥ — Agastya; ca — and; vasiṣṭhaḥ — Vasiṣṭha; ca — also; mitrā-varuṇayoḥ — of Mitra and Varuṇa; ṛṣī — the two sages.
Translation: 
By the semen of Varuṇa, the great mystic Vālmīki took birth from an anthill. Bhṛgu and Vālmīki were specific sons of Varuṇa, whereas Agastya and Vasiṣṭha Ṛṣis were the common sons of Varuṇa and Mitra, the tenth son of Aditi.