ר' אלעזר בן דמא

Rabbi Elazar ben Dama, the nephew of Rabbi Yishmael, died from a snake bite in holiness and did not wish to employ names and incantations for the wound, as stated in Chapter 2 of Avodah Zarah. And some say that he is one of the ten martyrs and not Rabbi Yehudah ben Tema [(see there)]. And in the Jerusalem Talmud, it is stated that the one who died from a snake bite is Yehoshua ben Dama, the nephew of Rabbi Yishmael [(see there)].

And according to Rabbi Eliezer, he was killed because he was wearing tefillin, which were still on his head. In Chapter 2, the son of Dama asked Rabbi Yishmael, "What is the status of someone like me who has learned the entire Torah, regarding the study of Greek wisdom?" He replied, "Seek a time that is neither day nor night." [The genealogy written [in the book Yesod Olam with the glosses of the Rema] states that Eliezer ben Dama was a colleague of Rabbi Yochanan ben Zakkai.

This is false, for he was the nephew of Rabbi Yishmael, who was a student of Eliezer ben Hurcanus, who was a student of Rabbi Yochanan ben Zakkai].