Phialidium gregarium

Phylum Cnidaria
Class Hydrozoa
Order Hydroida
Family Campanulariidae
Genus Phialidium
Species gregarium 

Description: Rarly reaches 1.5 cm in diameter; bell is saucer-shaped and has four radial canals, gonads on outer portion of radial canals; about 60 marginal tentacles; mouth opens directly into the stomach.

Habitat: Pelagic, floats near shore.

Natural History: The smallest hydromedusae which is seen in great numbers during the summer.