Phylum Porifera - Phylum Ctenophora - Phylum Cnidaria I. Phylum Platyhelminthes - Protostome development - Deuterostome development D. Endoderm, mesoderm and ectoderm - Class Cestoda G. Hydra and Medusa E. Coelomate Animal A. Comb Jellies B. Development in animal tissues where the anus develops first. C. Group of animals that consist of the Jelly fish and Hydra D. All are embryonic germ layers. E. have a body cavity called a coelom with a complete lining called peritoneum derived from mesoderm F. The basal lineage of all animals. Lack true tissues. G. are the two main body plans in the Phylum Cnidaria H. Organisms in this class are of the phylum platyhelminthes and are known as tape worms I. Organisms known as the flat worms. Animals in this group consist of the planaria and liver flukes J. Development in animal tissues where the mouth develops first.