From Fensome et al., 2019:

"Helbycysta", Morgan in Riding and Helby, 2001d, p.79. Name not validly published: no description.
Taxonomic senior synonym: Fusiformacysta, by implication in Riding and Helby (2001d, p.79), who included the two species names, Helbycysta psilata and Helbycysta verrucosa (both names not validly published), in synonymy with Fusiformacysta terniana and Fusiformacysta challisiana respectively.