SB 9.21.35

tasya satyadhṛtiḥ putro
 dhanur-veda-viśāradaḥ
śaradvāṁs tat-suto yasmād
 urvaśī-darśanāt kila
śara-stambe ’patad reto
 mithunaṁ tad abhūc chubham
Synonyms: 
tasya — of him (Śatānanda); satyadhṛtiḥ — Satyadhṛti; putraḥ — a son; dhanuḥ-veda-viśāradaḥ — very expert in the art of archery; śaradvān — Śaradvān; tat-sutaḥ — the son of Satyadhṛti; yasmāt — from whom; urvaśī-darśanāt — simply by seeing the celestial Urvaśī; kila — indeed; śara-stambe — on a clump of śara grass; apatat — fell; retaḥ — semen; mithunam — a male and female; tat abhūt — there were born; śubham — all-auspicious.
Translation: 
The son of Śatānanda was Satyadhṛti, who was expert in archery, and the son of Satyadhṛti was Śaradvān. When Śaradvān met Urvaśī, he discharged semen, which fell on a clump of śara grass. From this semen were born two all-auspicious babies, one male and the other female.