I am just beginning to read Everyman's Talmud by Abraham Cohen. In his quoting of the TANAC he uses (GEN. R. VIII 13). I understand this to mean Gen 8:13 but when I look at it it does not seem to relate to the context of the discussion. I'm used to reading the King James Version of the Bible. Is the chapter and numbering system different in the TANAC ?

Hmmm... I haven't read the Everyman's Talmud, but I do have a copy of the Torah here at home, and I looked up the verse Gen 8:13. I also found the verse in the online version of the King James Bible. The verses are the same.
Initially I thought maybe Dr. Cohen was quoting a part of the Talmud rather than the Torah, but there's no book or chapter in the Talmud that begins with the letters "Gen", as far as I know. Maybe it's just a typo?

Thanks. I'm wondering the same thing too. Thanks for Checking for me.