Stenocypris orientalis Victor & Fernando, 1981b

Figures 26–28.

1981b Stenocypris orientalis n. sp. — Victor & Fernando: 158 –160, figs. 46–60.

Material examined: Three females from WN6, two females (ECNU 20170417/HN19–20) dissected; one female from WN7, one female (ECNU 20170417/HN21) dissected; three females and eight female valves from WZS4, two females (ECNU 20170416/HN22–23) dissected.

Dimensions: Female, LV, n = 3, length 1.315 –1.462 mm, height 0.548 –0.621 mm; RV, n = 2, length 1.294 – 1.425 mm, height 0.542 –0.626 mm.

Description: Carapace elongated. LV overlapping RV anteriorly and posteriorly.Anterior margin more rounded than posterior (Fig. 26A). LV with inner groove along ventral and postero-ventral margins (Fig. 26B). Calcified inner lamella anteriorly and posteriorly wide. Septa narrow along free margins (Fig. 26 C–D). Five long natatory setae on A2 not reaching to end of terminal claws. Sixth one reaching to mid-length of next segment. Claw G2 about three quarters of length of claw G1. Claw G1 slightly longer than claw G3. Claw Gm about half length of claw GM (Fig. 27B). One tooth-bristle on third endite of Mx smooth, and other with tiny setules (Fig. 27D). Terminal segment of L6 with one short h1 seta, long claw h2 and long h3 seta, about 1/3 length of claw h2 (Fig. 28B). Terminal stem of right UR with large, slightly grouped denticles (Fig. 28D). Terminal stem of left UR with four groups of denticles (Fig. 28E).

Distribution: This species has been found in the Philippines, Malaysia (Victor & Fernando 1981b) and India (Harshey & Thilak 2011). This species was found in Waning and Wuzhi Mountain on Hainan Island.

Remarks: The septa along the margins of the carapace in the Hainan Island species are shorter than those of S. orientalis found in the Philippines (Victor & Fernando 1981b). The ratio of H and L of the valves is 0.39 in S. orientalis from the Philippines and Malaysia (Victor & Fernando 1981b), 0.40 in Indian specimens (Harshey & Thilak 2011) and 0.416 –0.439 in specimens from Hainan Island.

This species is similar to S. bolieki Ferguson, 1962, having a long h3 seta on the L6. But the tooth-bristles on the third endite of Mx are toothed in S. bolieki, while one is smooth in S. orientalis . Additionally, the ratio between W and H is 0.34 in S. bolieki (Rasouli & Aygen 2017) and 0.390 –0.439 in S. orientalis .