looks like dino to me, but sometimes nuisance algaes are hard to ID. Give this a good read: http://reefkeeping.com/issues/2006-11/rhf/index.php
The long and short of it is to a) reduce nutrients (reduced feedings, wetter skim, GFO, DSB, fuge, Biopellets, sulfur denitrator, water change) and increase pH (kalkwasser).