Anthozoans (Soft corals, sea fans, sea anemones, corals).

Caution. Stinging animals!

Identified until now

• Leptopsammia pruvoti - Yellow coral - Κίτρινο κοράλι (identified by Maria Sini)
• Telmatactis cricoids - Blunt tentacled or club tipped Sea Anemone (identified by Maria Sini)
• Cerianthus membranaceus - Tube dwelling anemone - Ανεμώνη που ζει σε σωλήνα (identified by Maria Sini)

Anthozoa

The name comes from the Greek words άνθος (ánthos; "flower") and ζώα (zóa; "animals"), hence ανθόζωα (anthozoa) = "flower animals", a reference to the floral appearance of their perennial polyp stage. 

Anthozoa is a class within the phylum Cnidaria. Unlike other cnidarians, anthozoans do not have a medusa stage in their development. Instead, they release sperm and eggs that form a planula, which attaches to some substrate on which the cnidarian grows. Some anthozoans can also reproduce asexually through budding. More than 6,100 species have been described.

Read more: http://en.wikipedia.org/wiki/Anthozoa

• http://en.wikipedia.org/wiki/Beadlet_anemone
• http://en.wikipedia.org/wiki/Cerianthus: Cerianthus is a genus of tube-dwelling anemones in the family Cerianthidae. Members of the genus are found worldwide. They are predators, scavengers and omnivores.[2]
• http://www.european-marine-life.org/05/anthozoans-gallery.php