Evolution on the Half Shell...

Glossus is an unusual and relatively rare species, with a thick solid shell up to 10 cm (3.9 in) in length. The yellow-white shell is usually covered by a dark red-brown periostracum. It occurs in deep water from Norway south to the Iberian Peninsula and into the Mediterranean Sea. It lives in mud or sandy mud leaving just the lower margin of the shell and its short siphons exposed. This single specimen was dredged from mud in the 100 m (328 ft) deep channel between the islands of Arran and Bute, off western Scotland.