adamantine - a brilliant type of luster, like that of a diamond.

cnidoblast - a cell in the epidermis of cnidarians in which a nematocyst is developed.

fluorescence - luminescence in which light of a visible color is emitted from certain substances, called phosphors, when irradiated by electromagnetic radiation, especially ultraviolet light.

glabella - From a Latin word meaning hairless, in more familiar animals it denotes the smooth area between the eyebrows just above the nose.

nematocyst - a capsule within specialized cells (cnidoblasts) of certain cnidarians (such as jellyfish) containing a barbed, threadlike tube that delivers a paralyzing sting when propelled into attackers and prey; also called a stinging cell.

osculum - a large opening of a sponge through which excurrent water is expelled.

ostium - pores in the walls of sponges through which water passes.

spicule - tiny siliceous or calcareous needle-like support element of most sponges.

spongin - organic fibers which form the skeleton of sponges of the class Demospongea.

spongocoel - the large cavity of tubular sponges through which water passes before being expelled through the osculum.

taxonomy - the science of classifying organisms into an ordered system that indicates natural relationships; also known as systematics.

tentacle - an elongate, flexible extension surrounding the mouth or oral cavity of cnidarians, cephalopods, and echinoderms, used for feeling, grasping, or locomotion.

vug - a small cavity in a rock or vein, often with a mineral lining of different composition from that of the surrounding rock.