from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of numerous species of siliceous fossil sponges belonging to Ventriculites and allied genera.
from the GNU version of the Collaborative International Dictionary of English
- n. Any one of numerous species of siliceous fossil sponges belonging to Ventriculites and allied genera, characteristic of the Cretaceous period.
from The Century Dictionary and Cyclopedia
- n. A fossil sponge of the family Ventriculitidæ a so-called “petrified mushroom.” They are of various shapes—fungiform, cup-like, tubular, or funnel-shaped—and abound in the Cretaceous.
See ventriculus. (Wiktionary)