Neoperla bilineata Wu & Claassen, 1934

(Fig. 6)

Neoperla bilineata Wu & Claassen, 1934: 120 . Type locality: Sichuan (Suifu).

Complementary description. Head and terminalia agree well with original description and illustrations (Figs. 6 a & 6b). Aedeagus (Figs. 6 c–e): Aedeagal tube straight, with usual basoventral and dorsal sclerites (Figs. 6 c–d). Aedeagal sac membranous but with heavily sclerotized ventrolateral strip subapically (Figs. 6 d & 6e). Sac about as long as tube and apical half slightly curved ventrally blunt angle to tube in ventral face (Fig. 6 d); lateral surface of sac with a large patch of numerous small spines except dorsal surface at base and marginal area of apex (Fig. 6 e); most are medium-sized spines with neighboring lateral patches of granules at subapical and basal areas (Fig. 6 e).

Material examined. Holotype and 1 female paratype (with an allotype label) (USNM), China: Szechuan, Suifu, (Sichuan, Yibin) no date, D.C. Graham (Type No. 55238) . Paratypes: 2 males, China: Szechuan, Kwan-hsien ( Guanxian, now Dujiangyan), 3000 feet, 1930. IV.5–V.8, D.C. Graham.

Diagnosis and remarks. The species is a member of the N. montivaga group and similar to N. nigromarginata Li and Zhang, 2014, a species recently described from Henan Province, China. It is easily separated from that species by having a relatively straight aedeagal sac with swollen apex in male and an elongate, rod-like subgenital plate in the female (Figs. 6 d–e, 7b). In N. nigromarginata Li and Zhang, the male aedeagal sac is curved ventrally nearly forming a right angle to tube, and the subgenital plate of female is very short forming a small dark tab (figs. 1f & 2b, Li and Zhang 2014).