- habitat
- habitus
- Head
- Hectocotylus
- hepatic groove
- herbivorous
- hermaphrodite
- heterogomph
- heteromorphic
- Hollow tentacle
- holoplankton
- homocercal
- homogomph
- homology
- hood
- Hook
- hook appendage
- house or germ
- Hump
- hyaline
- Hyaline gland
- Hydranth
- hydroecium
- Hydroid
- hydroids
- Hydrotheca
- Hypobranchial gland
- hypocystic villi
- Hypostome
- hypural