This superfamily unites about 45 genera in the following families:[1] These thecate hydroids grow in erect colonies, branched in some species but unbranched in others.

The hydrothecase have a cusped or even rim and instead of a diaphragm a well-defined floor with a hydropore that is usually off-center.

The hydranths have a conical hypostome and a single whorl of thread-like tentacles.

The gonotheca are borne singly or in groups, they may or may not have protective hydrocladia or appendages.

The gonophores are usually fixed sporosacs, more rarely they are rather reduced medusoids.