| Diagnosis |
Mean live weight. 1500 to 4,500 g; body-wall thickness 1 cm. Body sub oval, stout, firma and rigid, arched dorsally (bivium) and flattened ventrally (trivium); bivium with characteristic brown wrinkles. Podia on bivium small, brown, with a disc of around 200 micrometer diameter; podia on trivium more densely distributed on the median radius and more sparsely distributed on the outer radii and interradii, with their calcareous disc around 300 micrometer in diameter. Mouth ventral, with 20 brown, stout tentacles. Anus surrounded by 5 radial groups of 3 or 4 papillae and a black band. Calcareous ring with large radial pieces and narrower interradials. Cuvierian tubules absent. Cloaca large and black. Bivium golden brown, with numerous brown spots; trivium whitish; mature gonads bright yellow. Spicules in form of tables and buttons; tables of dorsal and ventral tegument similar in shape and moderately sparse, disc small, irregular, with 4 to 6 irregular holes, supporting a short spire, ending in an irregular row of smooth spines; ventral-tegument buttons elongated ellipsoids, with 12 to 16 holes and median nodules; dorsal-tegument buttons generally more regular and less perforated; ventral and dorsal podia with large plates, multiperforated and indentated; tentacles containing both large very spiny rods and short nodose rods. |