[Cubo-/Scyphomedusae] Short filaments, barely longer than wide, located in groups (phacellae) on the stomach linings in some cubomedusae. Reportedly absent in Carukia; may perhaps decompose or be digested away in specimens of other cubomedusae in which the preservative does not penetrate rapidly enough to prevent it. Gastric filaments occurring in Scyphomedusae are typically longer. See also filament.