Resources

• A wonderful website from the Smithsonian Institute on Jellyfish and Comb Jellies
  Jellyfish and Comb Jellies
  
• Great group of references at the scientific journal Public Library of Sciences (PLoS One)
  The World Register of Marine Species
• Here is a nice reference on Sea Pens: 
  Williams GC (2011) The Global Diversity of Sea Pens (Cnidaria: Octocorallia: Pennatulacea). PLoS ONE 6(7): e22747. doi:10.1371/journal.pone.0022747
• Here is a nice reference on lace corals:
  Cairns SD (2011) Global Diversity of the Stylasteridae (Cnidaria: Hydrozoa: Athecatae). PLoS ONE 6(7): e21670. doi:10.1371/journal.pone.0021670
• Awesome video of Ctenophora and their iridescence