Zoantharia

Zoantharia is an order of Anthozoa. Unlike the stony corals, these species do not have a hard skeleton. Most are very small. Some species form colonies.
Zoanthids can be distinguished from other colonial anthozoans and soft corals. Most of them (but not the family Zoanthidae) include sand and other bits of material in their tissue to help build their structure. The main characteristic of the order is that their tentacles are organised in two distinct rows.