Leucosolenida is an order of sponges in the class Calcarea and the subclass Calcaronea. Species in Leucosolenida are calcareous, with a skeleton composed exclusively of free spicules without calcified non-spicular reinforcements.
According to Systema Porifera (2002), Lucosolenida contains 9 families, ranging from fully asconoid forms (Leucosoleniidae) to fully leuconoid forms. These body plans are on a continuum based on an increasingly complex skeletal system and compartmentalized choanocytes. A few sources (such as the Treatise on Invertebrate Paleontology, 2004) place non-asconoid families into a separate order, Sycettida.Treatise on Invertebrate Paleontology Part E, Revised. Porifera, Volume 3: Classes Demospongea, Hexactinellida, Heteractinida & Calcarea, xxxi + 872 p., 506 fig., 1 table, 2004, available here. . Leucosolenids have a poor fossil record, with only a few ambiguous grantiid fossils reported from the Jurassic and Carboniferous.
Families
Achramorphidae Borojevic et al., 2002 (formerly known as Staurorrhaphidae) Amphoriscidae Dendy, 1892 Grantiidae Dendy, 1892 Heteropiidae Dendy, 1892 Jenkinidae Borojevic et al., 2000 Lelapiidae? Dendy & Row, 1913 Leucosoleniidae Minchin, 1900 Sycanthidae Lendenfeld, 1891 Sycettidae Dendy, 1892 (sometimes known as Syconidae)
References
http://species-identification.org/species.php?species_group=sponges&selected=beschrijving&menuentry=groepen&record=Leucosolenida