as Roland says, if they are white, and not extremely brown and no traces of mould they should be fine. It also depends on the sp/hybrid.
I once planted some dormant erythronium japonicum in january and they did fine and flowered in march/april the same year.
what erythroniums dont like it seems is condensation and changing temperatures if stored in plastic bags with moist peat, as they will become mouldy and rot very quickly.... but if they have been stored quite cold, even just in a box with a bit of soil to keep them from drying out, they should be fine.
i planted a nice selection last october, and am hoping the torrential rain with flooded borders as a result will not have made them all rot!

(amonghst others i have planted harvington snowgoose, harvinghton superb and hendersonii..)
Pontus