Authors(s)	Koolwijk, T. van
Year	1982
Title	Calcareous sponges of the Netherlands (Porifera, Calcarea). Bull. Zool. Mus. Univ. Amsterdam, 8 (12): 89-98.

• Grantia compressa
• Leucosolenia variabilis
• Sycon ciliatum
• Sycon scaldiense