Urosome segments not fused. Head with a triangular rostrum. Antenna 1 peduncle article 1 weakly setose, ventral margin with 2 (rarely 3) spines, inner margin without spines; female antenna 1 peduncle article 1 ventral margin weakly concave, spines small, inner margin not crenulate; male antenna 1 peduncle article 1 ventral margin not concave, spines small, inner margin strongly crenulate. Female antenna 2 peduncle article 4 distal ventrolateral angle with process or spine, article 5 without spine; male antenna 2 peduncle article 4 distal ventrolateral angle with long acute process, article 5 without spine. Gnathopod 1 palm transverse, evenly convex. Pereiopods 3 and 4 dactylus shorter than propodus and carpus combined. Uropod 1 peduncle outer margin with 10 to 12 spines, inner margin with 3 or 4 long spines; uropod 2 peduncle with 3 to 5 dorsal spines.
Up to about 10 mm.
Constructs tubes in intertidal mud flats, salt-marsh pools, brackish ditches; tolerates a wide range of salinity from near fully saline to almost fresh water. Locally abundant.
North Atlantic, American and European coasts; from Bothnian Bay to Mediterranean; Black Sea; Azov Sea.