1. Some other diploblastic creatures
Ctenophores

2. Attributes of ctenophores
Diploblastic
Comb jellies--eight rows of ciliated plates
Lack “true” nematocysts
Active filter feeders
Some tentacles, some lack tentacles--tentacles are paired structures
planktonic

3. Triplobastic creatures
Platyhelminthes (flatworms)

4. Characteristics of the Platyhelminthes
Triploblastic--ectoderm, endoderm and mesoderm
Acoelomate--mesenchymal (separate or syncitial)
Gastrovascular cavity depends upon the group--extracellular and intracellular digestion
Excretory system of flame cells
Some cephalization, nerve net subepidermal. Ladder like set of parallel nerve fibers in the mesoderm

5. Classes of Platyhelminthes
Turbellaria--marine and freshwater, free-living--one opening gut
Trematodes--parasitic, marine and freshwater--one opening gut
Cestoda--parasitic, marine and freshwater--lack a digestive tract