Antennal sinus may be well developed or weak; mandibular molar well developed and triturative; outer plate of the second maxilla bears only one type of seta apico-Iaterally, and the outer plate of the maxilla is not large; rugosities are absent from the maxillipedal palp and gnathopods; gnathopods are of medium size, the first not dominant, the carpi of medium length and not markedly lobate, the propodi attached to the carpi normally (ie. not cantilevered), and setae of the palms are not bifid; domination of the posterior lobes of coxae 5-7 is variable; oostegites broad; sternal gills simple orabsent; urosomites not fused.
Amphipoda
Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies.