Web Master:
Hey Sheena, if they are empty or almost empty when you squeeze them then just throw them away but if they still have some "heart" then there's still a chance they will grow.
Also see how extensive the mould is - if its rampant then they are done for - but if its only a fine and superficial dusting then they may well be OK.
Best bet is to plant them AND buy some new ones - you can never have enough spring bulb flowers, they lift the spirits of all who see them.
The image below comes from the bulb capital of the world - Keukenhof, Netherlands.