Horse Conch Egg Case

Pleuroploca gigantea egg case

These are Horse Conch egg casings.  Generally the only other egg case that looks similar to this one is the Tulip.  At first glance, if it is very large in size it is most likely the horse conch not tulip. The way to tell for sure is that on horse conch egg casings look closely at each capsule.  If it has encircling ridges as shown in the photos below it is the horse conch egg case.  The tulip's capsules are smooth in nature

 
Horse Conch egg case close up


A variety of Horse Conchs along with an egg mass



Horse Conch seashell egg casing