Ampullaceous \Am`pul*la"ceous\, a. [L. ampullaceus, fr. ampulla.]

Like a bottle or inflated bladder; bottle-shaped; swelling. --Kirby.

Ampullaceous sac (Zo["o]l.), one of the peculiar cavities in the tissues of sponges, containing the zooidal cells.

Source: Webster's Revised Unabridged Dictionary (1913)