Ampullaceous \Am`pul*la"ceous\, a. [L. ampullaceus, fr. ampulla.] Like a bottle or inflated bladder; bottle-shaped; swelling. --Kirby. [1913 Webster] {Ampullaceous sac} (Zool.), one of the peculiar cavities in the tissues of sponges, containing the zooidal cells. [1913 Webster] Ampullar