| Diagnosis |
Mean live weight: 100-400 g. Body-wall thickness 0.2 cm. Body firm, rigid with quadrangular section, flattened ventrally (trivium); body wall easily disintegrates outside sea water. Radii of bivium with characteristic double row of large papillae, each radius ending in a small red or orange papilla. Trivium delimited by characteristic double row of large papillae; stout podia arranged regularly on 3 radial bands, with 10 rows in the medio-ventral band and 5 in the lateral. Mouth ventral, surrounded by a row of papillae and 20 green, stout tentacles. Anus terminal. Calcareous ring with large radial pieces and narrow interradials. Cuvierian tubules absent. Cloaca large and greenish. Bivium dark green to black; trivium lighter. Spicules with very characteristic tables with a narrow disc showing 4 holes, bearing a spire generally ending in a moderately spiny crown; tables with larger disc and simpler crown also present; presence of many C-shaped spicules; rosettes absent; tables in dorsal with have a large multiperforated disc, bearing a large spire; ventral papillae with long, smooth rods; ventral podia with denticulate rods and large multiperforated plates; tentacles with smooth and granular rods. |