Infinite number of Jīva (souls) which have a common body- There are two types of Nigoda Jīvas-
1. Caturgatinigoda- Those Nigoda fīvas which, after having undertaken transmigration in all the four kinds of mundane existence, again reincarnate in the Nigoda. (It is propounded that all Jīvas (souls) stay in the Nigoda for infinite time; only a few of them are fortunate to get relieved from it and get reincarnation in other species).
2. Nityanigoda- Those Nigoda Jīvas, which have yet never left Nigoda; they have ever remained in Nigoda (i.e., they have undertaken transmigration in Nigoda only).
atthi aṇaṃtā jīvā jehi ṇa patto tasāṇa pariṇāmo. bhāvakalaṃkaapatirā ṇigodavāsam ṇa muṃcaṃti...
(SaKham 5.6.127)
ṇigodesu je ṭṭhidā jīvā te duvihā-cauggaiṇigodā ṇiccaṇigodā cedi. tattha cauggaiṇigodā ṇāma je deva-ṇeraiya-tirikkha-mannssesūppajjiyūna pimo nigodesu pavisiya acchamti....niccanigodā nāmaje savvakālaṃ ṇigodesu ceva acchaṃti.
(Dhava Pu 14 p 236)
See - Sthāvara Jīva.