What are the differences between flatworms and coelenterates?

The difference between flatworms and coelenterates:
– Bilateral symmetry (in coelenterates, radiation)
– The first three-layer animals (coelenterates two-layer)
– The body cavity is filled with a loose mass of cells (in coelenterates, the division of the body cavity into sections)
– Stem nervous system (in coelenterates, primitive, in the form of nerve cells scattered throughout the body)
– Excretory organs – through the surface of the body (in coelenterates through the oral opening)
– Are hermaphrodites (coelenterates are mainly dioecious)
– Complex developmental cycle with a change of hosts, intensive reproduction (in coelenterates, a simple developmental cycle with a larval stage, budding or sexual reproduction)