Polyonyx socialis sp. n., male paratype, SMF 52401, South China Sea, south coast of Vietnam, Nhatrang Bay, Mun Island. a Third thoracic sternite b Telson c Right third maxilliped, dorsal view (setae omitted) d Left (larger) cheliped, dorsal and ventral views e First and second right walking legs, dorsal view f Detail of dorsal view of propodus and dactylus of right third walking leg. Scale bars: 0.5 mm (a–c, f), 2.0 mm (d), 1 mm (e).