What does ampullaceous mean?
The definition of ampullaceous
Am`pul*la”ceous, a.
Etym: [L. ampullaceus, fr. ampulla.]

Like a bottle or inflated bladder; bottle-shaped; swelling. Kirby. Ampullaceous sac (Zoöl.), one of the peculiar cavities in the tissues of sponges, containing the zooidal cells.