Deltidium sentence example
- The ventral valve is usually the larger, and in many genera, such as Terebratula and Rhynchonella, has a prominent beak or umbo, with a circular or otherwise shaped foramen at or near its extremity, partly bounded by one or two plates, termed a deltidium.
- f, foramen; d, deltidium; t, teeth; a, adductor impressions (= occlusors, Hancock); c, divaricator (=cardinal muscles, King, = muscles diducteurs principaux, Gratiolet); c', accessory divaricators (muscles diducteurs accessoires, Gratiolet); b, ventral adjustor (=ventral peduncular muscles, or muscles du pedoncule paire superieure, Gratiolet); b', peduncular muscle.
- These plates are secreted by the ventral lobe of the mantle, and were named by von Buch in 1834 the " deltidium."
- The form of the deltidium varies in different genera.
- The American use of the term deltidium for the structure which Europeans call the pseudo-deltidium makes for confusion.
- Deltidium present, but no pro-deltidium.