VentriculiteVen*tric"u*lite\, n. [See Ventriculus.] (Paleon.) Any one of numerous species of siliceous fossil sponges belonging to Ventriculites and allied genera, characteristic of the Cretaceous period. Note: Many of them were shaped like vases, others like mushrooms. They belong to the hexactinellids, and are allied to the Venus's basket of modern seas.