Beads with longitudinal indentations have a variety of names—and people seem to prefer some over others. Almost anytime I have discussed this topic, I find there's a lot of disagreement.

I think it would be appropriate to call this bead a "cylinder with melon-form indentations." However, your point is taken. Among drawn beads (that remain cylindrical in shape, being derived from dented canes), even when the ends are cut (rounding or at least semi-rounding the shape) these have still been referred to as "melon-form" beads. The class includes early chevron beads, but also many plain beads.

In fact, it's not so unusual for melon beads to be twisted, in their manufacture, to make the indentations spiral, just a bit or a lot. It's also pretty common among Ghana powderglass beads, that the maker turns the bead while it's hot, inside the mold (and perhaps outside of it), to cause the structure to twist. Or, the dent might be haphazard and placed without much care, and thus be non-parallel.

It hadn't occurred to me that the dents represent decorations that have fallen out. And looking again, I would be inclined to not think so.

Be well. Jamey