Whelk egg case string

Whelk egg case string
Photographer: Sharon Kiyoshk-BurrittRights holder: Sharon Kiyoshk-Burritt

Egg case found on beach on Sanibel Island, Florida.  Identification tentative but based on http://www.projectnoah.org/spottings/8304104, http://sanibelseaschool.org/, and other online sources.