Mermaids Wine glasses
Reference from "The Cayman Islands Natural History and Biogeography" Edited by Martin A. Brunt and J.E. Davies
A 1994 publication from Springner Science & Business Media
These structures with aspect of satellite dishes are
in fact green algae each is a gigantic, single-celled organism.
This site will give more information on this very interesting organism
And this site will have more information on this algae