TY - CHAP AB - Acarnidae Dendy (Demospongiae, Poecilosclerida, Microcionina) contains 37 nominal genera of which 13 are considered here to be valid, and probably several hundreds of species. Acarnids are distributed worldwide, although several genera are predominant in colder temperate waters, and several have very restricted (apparently endemic) geographic ranges. Major morphological characters diagnostic for the family include massive, burrowing, excavating or encrusting growth forms with fistules, as well as non-fistulose genera with digitate, flabellate, massive or encrusting growth forms; ectosomal skeleton with tangentially arranged tylotes with spined bases; choanosomal skeleton reticulate (in massive) or plumose (in encrusting growth forms), with or without echinating spicules; megascleres include styles; and microscleres are palmate isochelae and toxas, sometimes lost or sometimes with other microscleres such as bipocillae, modified anisochelae, microrhabds and raphides. A1 - Hooper, J.N.A. JO - Systema Porifera. A Guide to the Classification of Sponges C1 - (2 volumes). Kluwer Academic/Plenum Publ., New York. 1708+XLVIII. ISBN 978-1-4615-0747-5 (eBook electronic version) TI - Family Acarnidae Dendy, 1922. Pp. 412–431. In: Hooper, J.N.A.; Van Soest, R.W.M. (2002 [2004]) UR - https://www.marbef.org/data/aphia.php?p=sourcedetails&id=404771 PY - 2002 [2004] Y2 - 2024-03-28 ER -