The hexactinellid Leiobolidium Schmidt (Porifera) is a Hyalonema Gray Author Reiswig, Henry M. Redpath Museum and Biology Department, McGill University, 859 Sherbrooke St West, H 3 A 2 K 6 Montreal, Quebec (Canada) cxhr @ musica. mcgill. ca text Zoosystema 2000 22 2 411 417 journal article 10.5281/zenodo.5394538 1638-9387 5394538 Genus Hyalonema Gray, 1835 TYPE SPECIES . — Hyalonema sieboldi Gray, 1835 by monotypy. DIAGNOSIS. — From Ijima 1927. Hyalonematid with variously shaped body; dermal surface entirely exposed on the exterior, without conical projections and pleural prostals; gastral surface flatly exposed, depressed or outbulged; basal tuft compact, twisted after full growth.