| 释义 |
‖ deltidium Conch.|dɛlˈtɪdɪəm|
[mod.L. dim. of Gr. δέλτα delta, in reference to its shape. (Cf. Gr. κυνίδιον little dog, from κυν-.)]
The triangular space, usually covered in by a horny shell or operculum, between the beak and the hinge of brachiopod shells.
1851Richardson Geol. viii. (1855) 232 The form and structure of the area and deltidium afford good generic characters. 1888Rolleston & Jackson Anim. Life 693 The groove is usually converted into a foramen by a ‘deltidium’ which consists of two calcareous pieces. |