| Diagnosis |
Mean live weight 300 to 800 g; body-wall thickness 0.3 cm. Body very elongate, narrower anteriorly than posteriorly. Tegument very smooth. Podia and papillae randomly distributed on bivium, the podia ending in a disc of around 480 micrometer diameter; podia on bivium numerous, short and stout, distributed on the radii and interradii, their calcareous disc and around 700 micrometer in diameter. Mouth ventral, surrounded by 20 black tentacles. Anus sub dorsal. Calcareous ring with large radial pieces and triangular interradials. Cuvierian tubules very thin and long. Entirely black. Spicules on dorsal and ventral tegument with tables and buttons; tables with circular large disc, having 8 holes or more, spire with 4 pillars, and ending in a crown with large central hole; buttons regular, with 6 or 8 holes, or irregular; plates large in ventral podia, with many holes; dorsal podia also with long rods; tentacles containing few rods. |