According to the Anguttara Commentary (AA.i.52), there was once a period of great disaster in Ceylon, known as the Canndāla-tissabhaya. There was no food to be had, and Sakka provided the monks with a raft on which to cross the sea. Sixty monks, however, remained in Ceylon, guarding the scriptures. Twelve years later, when the danger was past, the monks who had left the land returned and dwelt in the Mandalārāma in Kallagāma (Kālakagāma?). There the two parties of monks met and, on comparing their records of the scriptures, these were found not to differ by so much as a syllable or even a single letter.
Comparison of this story with the account given elsewhere (E.g., VibhA.445ff) of the Brāhmanatissacorabhaya strongly suggests that both refer to the same account. For details see s.v. Brāhmanatissa.