Rav Huna and Rav Sheshet
There were around a dozen rabbinic scholars in Babylonia at this time, the second generation of amoraim (scholars) who appear frequently in the Talmud. Although most of them appear to have been primarily students of Rav, most of them also seem to have learned from Shmuel. Rav Sheshet is more of a mystery.
(died a few years prior to 300):
Rav Huna was from a town near modern Bagdad on the Tigris River called Tikrit. After Rav’s death, he was the main lecturer at the academy in Sura but was not appointed officially its head until Shmuel’s death. He presided over the academy for more than 40 years and built it up to legendary proportions. The Talmud claims that when his students rose to stand in respect of him, their sheer number would cause a dust cloud that obscured the sun in Israel (Ket. 106a). It is reported that the Persian king authorized him to wear his belt low as a sign of distinguished rank.
Rav Sheshet attended the lectures of Rav Huna, and was a senior student of his (cf. TB Ketuvot 69a). He lived in Nehardea but it is unclear whether this was before or after its destruction in about 260 (Ned 78a, Meg. 29a). There is no documentation of interaction with Shmuel (who died some time prior to this destruction). He was considered to have had a wide breadth of knowledge of Mishnah and Braitot, but seems not to have been a student of Rav’s. He cites several sayings of Rabbi Eleazar ben Azariah (Pes. 118a), which may indicate he had access to traditions brought by Rabbi Akiva during his trip to Nehardea.