| compound eye | | primitive brain |
| amoebocyte | | term usd to describe the attachment of sponges to other objects |
| radula | | tiny tubular structure that pulls fluid from the coelom |
| sponge | | water exits these larger pores |
| chrysalis | | thick protective covering of cells posessed by endoparasites |
| spongin | | hatchling or juvenile |
| fluke | | also called collar cells; lines the internal cavity of the sponge |
| hydrozoa | | stinging cells located on the tentacles |
| metamorphosis | | a large group of soft-bodied polyps found in coastal areas all over the world: highly muscular and quite complex |
| malpighian tubule | | eye made up of alot of small individual units |
| planulae | | phlum which jellyfish belong to |
| polyp | | slender, finger- like extensions from the arthropod's gut and are bathed by blood |
| scyphozoans | | a dramatic physical change |
| siphon | | a chewing mouthpart |
| mandible | | makes the sponge's skeleton; made of flexible protein fiber |
| nymph | | another form of a jellyfish;tubelike, attaches itself to rocks or something of the sort |
| mantle | | sections in a tapeworm's body |
| choanocyte | | larvae of hydrozoans |
| cnidocyte | | a tongue- like organ located in the mouth of mollusks |
| thorax | | penetrates the sponge's body wall |
| medusa | | a structure that extends from an arthropod's body |
| molting | | largest class of cnidarians |
| gemmule | | sponge cells that have an irregular shape: like amoebas |
| cephalothorax | | internal body walls |
| spicule | | clusters of amoebocytesencased in protective coats |
| sea anemones | | central section that contains the mollusk's organs |
| oscula | | small barbed harpoon within the cnidocyte |
| trematoda | | produces a sticky substance which aids in the attachment to objects |
| ostia | | the simplest of all animals |
| sessile | | one body form of a jellyfish;umbrella shaped, free-floating, jelly-like |
| tegument | | the class which "true jellyfish" belong to |
| anthozoans | | tiny needle made of silica or calcium carbinate |
| nematocyst | | head |
| appendage | | a protective capsule |
| septa | | the largest flatworm class |
| proglottid | | head thorax |
| basal disk | | heavy fold of tissue that forms the outer layer of the body |
| cerebral ganglion | | hollow tubes that draw in seawater |
| nephridium | | the shedding, discarding of an exoskeleton periodically |
| visceral mass | | the class where the most primitive hydrozoa are located |
| cnidarian | | parasidic worms |
