The categories (sub-phylums) of the Jīvas (souls) born in the same Yoni (substratum suitable for the birth of the Jīva (soul)).
ekasyāmeva yonau anekani kulāni bhavanti.
(Prajñā 1.49 Vṛ Pa 41)
...beimdiyānam pajjattāpajjattānam satta jaikn- lakodijonīpamuhasatasahassā bhavamtīti makkhātam.
(Prajñā 1.49)