Bugula simplex is an erect bryozoan found in subtidal waters of the north Atlantic. The species forms thick funnel-shaped colonies up to 3 cm in height that become tufted. The colonies are composed of multi-serial dichotomous branches that are light orange-brown or straw coloured. The branches narrow at the base and broaden at the top. Autozooids are 0.5 – 0.8 by 0.1 – 0.2 mm, with spines at the tip.
Bugula simplex is characteristics of ports and harbours in the North Atlantic where it colonises pier piles and other artificial substrates. Bugula simplex occurs on the Atlantic coast of North America (where it was wrongly identified as B. flabellata for many years) and in the Mediterranean and Adriatic Seas. It is perhaps a more recent immigrant to south Australia and is thought to be non-native in western Europe. Until reported in the British Isles by Ryland (1958), B. simplex was known only from the Mediterranean and the eastern seaboard of North America. Recent British records include Brighton Marina and Suffolk Yacht Harbour.
Bugula simplex is generally only found for a short period over the summer, with erect portions thought not to survive the winter.