- Kingdom: Animalia
- Phylum: Echinodermata
- Subphylum: Echinozoa
- Class: Echinoidea
- Order: Camarodonta
- Family: Parechinidae
- Scientific name: Psammechinus miliaris
- Norwegian: Tangsjøpiggsvin
The somewhat depressed shell has a horizontal diameter of up to 5 cm. The short spines usually have violet points. Both shell and spines have a green tint.
Can be found on wide range of substrate, but seems to prefer hard bottom on current-exposed locations. The depth range is from the subtidal zone to 100 meters.
Widespread along the East costs of the Atlantic Ocean, from Iceland to Morocco, excluding the Mediterranean. It is also found at the Azores, but not in North America or Greenland.