Photo by J. Winston, courtesy of the American Museum of Natural history. Used with permission. Colonies of S. regularis are erect and branching, forming short pink tufts on various substrata .
Zooids are narrow in the proximal portion, wider distally.
Individual zooids measure an average of 0.51 X 0.20 mm. There are 2 - 7 distolateral spines, simple or branching, present around the mural rim. The innermost proximal spine in specialized to act as a shield or scutum over the membranous frontal area. This single spine covers most of the opesia, is large and paddle-shaped with pointed edges. Polypides have obliquely truncate lophophores which average 0.464 mm in diameter.