OK, I found it.
The May, 1989 issue of Hawaiian Shell News had an article by Theresa Marché
entitled Aquarium Observations.
It had pictures and observations about a meat-eating Cypraea arabica, a
naked Ilyanassa obsoleta (which did not survive long), and a Murex
palmarosae which dissolved some spines and added a varix in a little over 3
months after 3½ years of no shell growth despite regular feeding.

John