So, Google tells me that whelks are medium to large, snail-like mollusks, and in our part of the world there may be three or four species. I don't know which species created the chain in my hand. Of the whelk species mentioned for the Yucatan, the Lightning Whelk -- the State Shell of Texas -- is by far the most documented, so that name is a good bet.

Throughout the world many mollusks from several taxonomic groupings are referred to as whelks, so the name whelk has no technical basis at all.

I read that the female Lightning Whelk begins creating her string of egg cases by attaching the first part emerging from the pore in her foot to rocks, old shells or algae. A typical strand bears 50 to 175 capsules and there are 20 to 100 eggs in a capsule. The last few capsules on the unattached end are usually empty of eggs. Most eggs never hatch, but serve as food for the single individual in that capsule that does. Baby whelks look like tiny editions of the adults.