Abstract
A new species of Cubozoa found in an aquarium at Hagenbecks Tierpark (Zoo), Hamburg, Germany, is described herein as Carybdea morandinii. The species is distinguished from all known cnidarians in the anatomy of its polyp stage. The gastric cavity of the cubopolyp is divided horizontally into two chambers by a shutter-lens-like diaphragm. Metamorphosis was total and resulted in a single, four-tentacled medusa as in other known cubozoans. Both polyp and medusa stages bear zooxanthellae, which seemed important in the metamorphic process.