Kahelelani is a tiny snail found only in the Hawaiian Islands.  It's scientific name is leptothyra verruca.  Giant winter swells from the north bring these shells over the reef from the deep water and onto the beaches where they can be collected.  Not every swell will coincide with proper tides and other factors to produce quantities of shells and one can never know exactly when it will be good.  Because of these factors, the majority of shells are usually gathered over a small number of days when everything lines up!  Last season, I got the majority of my stash in about twenty days of collection.  I continually monitor conditions so I don't miss these big episodes.   On typical days, there aren't enough shells on the beach to make it worthwhile.  When it is happening, you need to put in as much time as you can and get as many shells as possible.  The next swell can take everything away!