A suborder of amphipod crustaceans. Most hyperiids can be recognized by the large eyes which cover nearly the entire surface of the head. The first maxillae and especially the maxillipeds are greatly reduced in comparison to the suborder Gammaridea. In the prehensile pereiopods, the claw is formed by the fifth and sixth segments, the carpus and propodus, rather than by the sixth and seventh segments or the propodus and dactyl, as in the Gammaridea. The second and third somites of the urosome are always fused, a condition rarely found in the Gammaridea.