-ika (-ικα) it's a plural suffix of adjectives which indicates nouns that derive from or belong to the stem of the adjective, in this case rizit-ika (ριζίτ-ικα) are those who derive from the roots, ie the songs. An ancient example of this grammatical phenomenon in Cretan literature can be found on a lost writing of Epimenides with the title Cretica (Κρητ-ικά) those who derive from Crete. Encyclopedia Britannica: «Epimenides, (flourished 6th century bce?), Cretan seer, reputed author of religious and poetical writings, including a Theogony, Cretica, and other mystical works.
