The single member in the genus Atubaria is unusual in lacking the tubes typical of other pterobranchs, living as a naked zooid on corals. Recently, Atubaria has been regarded as a questionable species by Tassia et al. (2016) and is no longer considered valid.

The collar bears a number of large arms, each of which includes a row of tentacles along one side. The number of arms varies between species, with anything from one to nine pairs. The tentacles are covered in cilia