Srimad-Bhagavatam: Canto 4 - Chapter 1 - Verse 61

Sanskrit:

तेभ्योऽग्नय: समभवन्चत्वारिंशच्च पञ्च च ।त एवैकोनपञ्चाशत्साकं पितृपितामहै: ॥ ६१ ॥

ITRANS:

tebhyo ’gnayaḥ samabhavancatvāriṁśac ca pañca cata evaikonapañcāśatsākaṁ pitṛ-pitāmahaiḥ

Translation:

From those three sons another forty-five descendants were generated, who are also fire-gods. The total number of fire-gods is therefore forty-nine, including the fathers and the grandfather.

Purport:

The grandfather is Agni, and the sons are Pāvaka, Pavamāna and Śuci. Counting these four, plus forty-five grandsons, there are altogether forty-nine different fire-gods.