It has the same sort of calcified byssus as anomia, and also the hole to accommodate it in the smaller valve.
The Terebratul are included in the genus anomia in the system of Linnus.
Note the barnacles, silver shells (anomia), etc., on the box and rope.
anomia has an irregularly rounded shell, with one convex and one flat or concave valve.
The singular structures composing this genus were formerly taken for bivalves, and named anomia Tricuspidata, &c.
The bent form of the embryonic heart recalls the heart of spiders; it lies at first free, as in the mollusc anomia.
This singular shell, known only in a fossil state, in the Palozic beds, is placed by Linnus in the genus anomia.
anomia a·no·mi·a (ə-nō'mē-ə)
See nominal aphasia.