@inbook{ERMS:SourceID:9096, author = {Reiswig, H.M.}, note = {The PDF supplied here is a proof - NOT the definitive printed text - of a chapter of the Systema Porifera}, title = {Class Hexactinellida Schmidt, 1870. pp 1201-1202 In Hooper, J.N.A. & van Soest, R.W.M. (ed.) Systema Porifera. A guide to the classification of sponges. 2 (Kluwer Academic/ Plenum Publishers: New York, Boston, Dordrecht, London, Moscow.}, url = {https://www.marbef.org/data/aphia.php?p=sourcedetails&id=9096}, year = {2002} }