(Haeckel, 1887)
Main spicules quadrangular prismatic, almost violin-shaped, with four very broad, prominent, lamellar wings, constricted in middle part, and broadened towards both ends; apex truncate pyramidal; base with large leaf-cross. Eighteen smaller spicules shorter (about three times shorter), at the base quadrangular pyramidal, prismatic in distal part. Central capsule spindle-shaped, opaque. Length of 18 secondary spicules: 0.04 to 0.08 mm.