<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Plexauridae Gray 1859</title> <meta content="text/html; charset=UTF-8" http-equiv="content-type"/> </head> <body> <h1>Family Plexauridae Gray, 1859</h1> <p> <b>Diagnosis</b> (after Kükenthal 1924; Bayer 1956, 1981; Sánchez & Cairns 2004; Williams and López-González 2005): Colonies display a variety of diverse forms, generally with thick branches arising laterally, dichotomously (in some, pinnately). Polyps completely retractile or form distinct calyces into which anthocodiae can be withdrawn. Axis with wide, chambered central chord; peripheral zone of loculated horny material, usually containing non-scleritic calcareous matter (common tendency toward heavy calcification of base in older colonies). Coenenchyme thick, perforated by system of longitudinal canals surrounding axis, delimiting outer coenenchymal layer from inner one (axial sheath), which differ in spiculation. Sclerites usually include some form of club; some with spindles only, oval bodies, rods or large quadriradiates.</p> </body> </html>