Blastomussa coral , Blastos for short, are a low light large polyp coral, LPS.  Blastomussa Wellsi and Blastoumussa Merletti are the two main species of Blastomussa sold in the reef aquarium industry today.  They come in a variety of colors and patterns.  The Wellsi has a large polyp and the Merlettie has a smaller polyp.  They require low to medium light and low flow.  They greatly benefit from regular feedings.