| > 5000 µm | |
| 1000-2000 µm | |
| 15-30 µm thick | |
| 2000-5000 µm | |
| 5-15 µm thick | |
| 500-1000 µm | |
| absent | |
| cladi > 100 µm | |
| cladi 50-100 µm | |
| present | |
| single category | |
| two categories |
| > 200 µm | |
| 10-15 µm | |
| 15-30 µm | |
| 3-5 µm | |
| 30-50 µm | |
| 5-10 µm | |
| 50-75 µm | |
| 75-100 µm | |
| absent | |
| amphiasters | |
| aspidasters | |
| metasters | |
| oxyasters | |
| plesiasters | |
| pycnasters | |
| spherasters | |
| spirasters | |
| sterrasters | |
| sterrasters-elliptic | |
| sterrasters-spherical | |
| strongylasters | |
| two categories | |
| tylasters |
| confused mass of triaenes | |
| predominantly oxeas | |
| pulpy interior | |
| radiating triaenes |
| black | |
| blue | |
| brown | |
| greenish | |
| grey | |
| off-white | |
| orange | |
| pale yellow | |
| red | |
| slate | |
| white |
| brown | |
| ochre | |
| orange | |
| white | |
| yellow |
| cheesy | |
| crumbly | |
| firm | |
| hard | |
| incompressible | |
| soft |
| < 0.5 mm thickness | |
| 0.5-1 mm thickness | |
| 1-3 mm thickness | |
| 3-10 mm thickness | |
| crust of amphiasters | |
| crust of aspidasters | |
| crust of microrhabds | |
| crust of oxyasters | |
| crust of sterrasters | |
| crust of strongylasters | |
| crust of tylasters | |
| middle layer of trichodragmas | |
| palisade of oxeas |
| > 200 m | |
| 0-10 m: shallow sublittoral | |
| 11-50 m: deep sublittoral | |
| 50-200 m: continental platform | |
| intertidal |
| > 5000 µm | |
| 10-20 µm thick | |
| 1000-2000 µm | |
| 20-50 µm thick | |
| 2000-3000 µm | |
| 250-500 µm | |
| 3000-4000 µm | |
| 4000-5000 µm | |
| 50-100 µm thick | |
| 500-1000 µm long | |
| absent | |
| oxeas | |
| single category | |
| strongyles | |
| strongyloxeas | |
| two categories |
| dead corals | |
| in crevices | |
| on rocks | |
| pebble bottom | |
| presence of silt | |
| shaded overhangs | |
| soft bottom | |
| under stones | |
| vertical walls |
| 10-20 µm | |
| 100-200 µm | |
| 20-30 µm | |
| 5-10 µm | |
| 50-100 µm | |
| absent | |
| acanthose | |
| centrotylote | |
| sanidasters | |
| single category | |
| toxiform microxeas | |
| trichodragmas |
| > 100 µm thick | |
| > 3000 µm | |
| < 500 µm | |
| 10-15 µm thick | |
| 1000-2000 µm | |
| 15-20 µm thick | |
| 20-50 µm thick | |
| 2000-3000 µm | |
| 50-100 µm thick | |
| 500-750 µm long | |
| 750-1000 µm | |
| calthropses | |
| cladi > 250 µm | |
| cladi 100-250 µm | |
| cladi 50-100 µm | |
| dichotriaenes | |
| orthotriaenes | |
| plagiotriaenes | |
| single category | |
| two categories |
| 1-5 mm | |
| central hole | |
| flush | |
| grouped in depression | |
| in a row | |
| inconspicuous | |
| naked rim | |
| on one side only | |
| on papillas | |
| scattered | |
| sieve-like areas |
| > 6000 µm | |
| 15-50 µm thick | |
| 1500-4000 µm | |
| 4000-6000 µm | |
| 5-15 µm thick | |
| absent | |
| mesotriaenes | |
| present |
| cup | |
| encrusting | |
| globular | |
| lobular | |
| massive | |
| mushroom-shaped | |
| ovate | |
| plate | |
| root-like papillas | |
| stalked | |
| subspherical | |
| tuberose |
| > 20 cm diameter | |
| < 1 cm diameter | |
| 1-3 cm diameter | |
| 1-5 cm high | |
| 10-20 cm diameter | |
| 3-10 cm diameter | |
| 5-10 cm high |
| clean | |
| conulose | |
| encrusted by pieces of shell | |
| excavated equitorial region | |
| folded | |
| hispid | |
| irregular projections | |
| overgrown and sedimented | |
| ridged | |
| rough | |
| smooth |