7 Oklahoma Animal Phyla Phylum Subphylum Class Animals Cnidaria   Hydrozoa freshwater hydra Platyhelminthes   Turbellaria planarians   Trematoda flukes   Cestoda tapeworms Nematoda     roundworms Mollusca   Gastropoda snails and slugs   Bivalvia fresh water muscles Annelida   Oligochaeta earthworms   Hirudinea leeches Arthropoda Crustacea   crayfish, water fleas, and copepods Chelicerata Arachnida spiders, scorpions, ticks, and mites Uniramia Insecta insects.................key Diplopoda millipedes Chilopoda centipedes Chordata Vertebrata Agnatha lamprey.................key Osteichthyes bony fish......key Amphibia frogs, toads, and salamanders......key Reptilia lizards, turtles, and snakes.......key Aves birds......key Mammalia mammals......key