Hi, I have shipped these type of glass bulbs before and left them in the box. First I wrapped bubble wrap around the boxes and then placed packing peanuts under-over-around each box seperately. Another idea is to double box them-adds to the weight-but just a thought-(you may want to also required insurance on them too-just in case).
(I also added a layer of bubble wrap on the inside top of the box of bulbs)
But like member-8880-said the safest is to wrap each one seperately.
Good Luck!