Mar Rav Huna Mari bar Mar Rav Yosef was the head of the yeshiva in Pumbedita [(and in Yuchsin in the letter of Rash"b from Mata Mechasia)] in year 1000 of the Seleucid era, which is year 4448. [And Yuchsin wrote from section 2, the order of the Geonim, and after him Rav Chiya from Mishan, and after him Mar Yanuka, who is Rabbah bar Netura'i (see above year 4460), and after him Rav Yehuda Gaon, and after him Rav Yosef, and after him Rav Shmuel bar Mari. Shada"k page 58b writes that Resh Dey was in Mata Mechasia and Rav Chanina was in Pumbedita and they received in year 4440].

Know that from Rav Huna bar Mari until Rav Menashe HaLevi, Rash"b counted 100 years, and from Rav Menashe until Rav Hai bar David, about 100 years. He wrote that from year 4448 onward all the calculations of the Geonim are certain without doubt. Rav Chanina Gaon from Nahar Pakod was head of the yeshiva in Sura in the days of Resh Dey Mari for 5 years from year 4448 until year 4452. According to the Ra'avah, Rav Chanina was the first of the generation of Geonim [(Tzemach David).

Also in Yuchsin in the order of tradition that the Rama"n copied, the first generation of the heads of Pumbedita was Rav Chanina, and after him Rav Hillai HaLevi, and after him Rav Ya'akov from Nahar Pakod, and after him Rav Shmuel Gaon. And Shada"k page 36b, Rav Tut Gaon was head of the yeshiva in Pumbedita and died in year 4475].