horseshoe crab shell. A large number of them seem to shed in September, and lots of their shells in a variety of sizes wash up. I haven't seen as many as usual this year; maybe the low salinity kept most of them farther south. You can take these and wash them out (to help keep the smell down, and get rid of sand), then pose them to dry. I've even seen people paint them.
Fata Morgana mirage over at Taylor's Island in the back.
... is an Italian phrase derived from the vulgar Latin for "fairy" and the Arthurian sorceress Morgan le Fay, from a belief that the mirage, often seen in the Strait of Messina, were fairy castles in the air or false land designed to lure sailors to their death created by her witchcraft.