SB 6.6.8

marutvāṁś ca jayantaś ca
 marutvatyā babhūvatuḥ
jayanto vāsudevāṁśa
 upendra iti yaṁ viduḥ
Word for word: 
marutvān — Marutvān; ca — also; jayantaḥ — Jayanta; ca — and; marutvatyāḥ — from Marutvatī; babhūvatuḥ — took birth; jayantaḥ — Jayanta; vāsudeva-aṁśaḥ — an expansion of Vāsudeva; upendraḥ — Upendra; iti — thus; yam — whom; viduḥ — they know.
Translation: 
The two sons who took birth from the womb of Marutvatī were Marutvān and Jayanta. Jayanta, who is an expansion of Lord Vāsudeva, is known as Upendra.