Promonhystera fluctispicula sp. nov.

(Figures 3–4, Table 1)

Type material. Holotype: one male on slide Yelin Bay 01–1 . Paratypes: two males on slide Yelin Bay 02–2 .

Type locality and habitat. Holotype located in intertidal zone of Yelin Bay, Hainan Province (19°36′26″N 110°55′38″E), muddy sediment and 0–2 cm section in the corer . Paratypes were all located in 2–5 cm section in the corer.

Etymology. The Latin adjective fluctus refers to a distinct feature of the species: the double-curved spicules.