General description: 

Colony encrusting, unilaminar to multilaminar and nodular, or erect, branching, often robust. Autozooids with umbonuloid frontal shield bordered by marginal areolae. Primary orifice with or without a lyrula; condyles variably developed. Oral spines present or absent. Avicularia adventitious, often polymorphic, usually suboral. Peristome often well developed. Ovicell prominent, imperforate, or with few pores.

(Hayward and Ryland, 1999)

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith