Declension of Greek Names

Does anyone know how to decline Greek names of the type Echo -us, Dido -us? My dictionary has the ‘-us’ in the genitive of Dido marked as having a long ‘u’, but not the other one, so there might be two declensions here. Gratias ago.

Great eyes; I think you’ve found a misprint. Are you using Chambers Murray?

Lewis & Short has both 'u’s long.

You could decline Dido as a Latin third declension (Dido, Didonis).
If you preferred Greek, you would have:
Dido (nom)
Didus (gen)
And Dido for the rest of the oblique cases (dat., acc., abl., voc.).

Cheers, adz000 (what a dull name!). I’m using a Collins Gem.

Is that originally a foreign name then? I remember hearing something about that declension being used in foreign names, e.g. Biblical/Hebrew names.