Srimad Bhagavatam Canto 04, Chapter 01, Text 08

SB 4.1.8

tusita nama te deva
asan svayambhuvantare
marici-misra rsayo
yajnah sura-ganesvarah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
 
During the time of Svayambhuva Manu, these sons all became the demigods collectively named the Tusitas. Marici became the head of the seven rsis, and Yajña became the king of the demigods, Indra.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
During the life of Svayambhuva Manu, six kinds of living entities were generated from the demigods known as the Tusitas, from the sages headed by Marici, and from descendants of Yajña, king of the demigods, and all of them expanded their progeny to observe the order of the Lord to fill the universe with living entities. These six kinds of living entities are known as manus, devas, manu-putras, amsavataras, suresvaras and rsis. Yajña, being the incarnation of the Supreme Personality of Godhead, became the leader of the demigods, Indra.
Srimad Bhagavatam Canto 04, Chapter 01, Text 07
Srimad Bhagavatam Canto 04, Chapter 01, Text 09