Chrissia formosa (Klie, 1938)

Figures 19–20.

1938b Stenocypris formosa n. sp. — Klie: 28 –30, figs. 8–11.

1974a Chrissia formosa (Klie, 1938) — Okubo: 5.

Material examined: Six females and five female valves from11DZ17, one female (ECNU 20171114/HN09) dissected; two females from WN6.

Dimensions: Female, LV, n = 2, length 1.562 –1.586 mm, height 0.631 –0.635 mm.

Description: In lateral view, carapace elongated. Greatest height posterior of mid-length. Dorsal margin arched. Ventral margin slightly concave. Calcified inner lamella anteriorly wide. Septa on margins of carapace absent (Fig. 19A). Eggs visible through pellucid valve (arrow a on Fig. 19A). Five long natatory setae on A2 exceeding tips of terminal claws, and one short almost reaching middle of next segment (Fig. 20A). Both tooth-bristles on third endite of Mx slightly toothed. L6 five-segmented, with two d setae on basal segment (Fig. 20B). UR asymmetrical. UR attachment with basal triangular reinforcement (Fig. 20E). Seta Sa shorter than 1/2 length of claw Ga, claw Gp shorter than 1/2 length of claw Ga (Fig. 20 C–D). Stem of left UR smooth (Fig. 20D), and right one with continuous line of denticles (Fig. 20C).

Distribution: This species has been previously reported from Japan (Okubo 2004; Smith et al. 2011), India (Karuthapandi et al. 2014), the Philippines (Victor & Fernando 1981b), Thailand (Savatenalinton & Suttajit 2016) and Taiwan in China (Klie 1938b). During this study, this species was found in Danzhou and Waning on Hainan Island.

Remarks: The maximum height of the valve is situated at mid-length in Klie (1938b) and Victor & Fernando (1981b). Hainan specimens are more similar to specimens found in Japan by Okubo (2004) and Smith et al. (2011), with maximum height situated slightly posterior of mid-length (Fig. 19).