| A | B |
|---|
| Porifera | simplest animal; filter feeders; sponges |
| Cnidaria | medusa or polyp stage; jellyfish; tentacles |
| Platyhelminthes | flatworms; 3 germ layers; mouth and anus not separate |
| Nematoda | round worms; parasites; psuedocoelomate |
| Annelida | segmented worms; earthworms; true coelom; crop and gizzard |
| Mollusca | snails, slugs, octopus; complex nervous system |
| Arthropoda | spiders, insects; complex organ systems and social behaviors |
| Echnidermata | radial symmetry; spiny skin; water vascular system |
| Animalia | kingdom of invertebrates; heterotroph, eukaryotic, multicellular |
| bilateral symmetry | body divides into two equal parts |
