35. Segmentation (limpets are just one piece, unlike crabs which are segmented) and molted external skeleton
36. Eukarya have nucleus (prokaryotes are the ones that don't)
Looking at all three possibilities: Segmentation, tiny, free-swimming larva, and molted external skeleton
Barnacles, limpets, and crabs all have tiny-free swimming larva. However, barnacles + crabs are anthropoids and have segmentation (limpets and mollusks do not). The two also molt their external skeletons while limpets and just enlarge them.
Does that make sense?
