(Figs. 2, 5–6, 8, 10, 12, 14–17)
Material. Holotype 3: China, Zhejiang, West Tianmushan, alt. 700m, 8 viii 2007, Yu Xin leg. Deposited at the Institute of Entomology, Life Sciences College of Nankai University, Tianjin, China. Paratypes: 4 3, 4 Ƥ, Zhejiang, West Tianmushan, alt. 380m, 25 / 28 vi 2008, Zhang Haomiao leg.; 13, Zhejiang, Qingliangfeng, alt. 600m, 12 viii 2007, Yu Xin leg.; 2 3, 1 Ƥ, China, Zhejiang, Qingliangfeng, alt. 900m, 13 / 14 viii 2007, Yu Xin leg. Other material: 1 Ƥ, China, Hunan, Mt. Hupingshan, 0 7 viii 2009, Yuanxin leg.; 1 3, 1 Ƥ, China, Guizhou, Tongren, Mt. Fanjingshan, alt. 1100m, 17 vii 2008, Zhang Haomiao leg.
Etymology. The specific epithet, corephaea, (a Latinized form of the Greek compound κορη = ‘maiden’ and Φαια ‘dusky’), = ‘dusky maiden’, in reference to the dark brownish wings of this damselfly species. A noun in apposition.
Diagnosis. A brownish winged Matrona species without any milky coloured reticulation at the wing bases, hindwing darker brown than forewing; in hindwing veins look paler than the wing membrane. Wing tips darkened, more extensively so in hindwing. Reticulation of wings relatively open as in M. oreades.
Description of male (Fig. 2, 5). Head: Eyes in the living specimens largely dark brown with lower section pale greenish. Labium mainly pale, median lobe darkened at base. Labrum mainly pale bluish, bordered with black; a dark median basal triangle; base of mandibles black with a pale spot. Anteclypeus black with a paler marking in the middle; postclypeus metallic bluish. Frons and vertex dark metallic green; antennae dark with an obscure, pale spot at base of pedicel (Fig. 8).
Thorax: Prothorax metallic green. Synthorax dull metallic green with bluish tint middorsally. Pale portions restricted to the level anterior to stigma and around metepimeron (Fig. 5). Ventrally pale yellowish. Legs largely black; hind coxa yellow, fore and middle coxa with yellow lateral markings. Hind tibiae moderately bent (Fig. 2, 5).
Wings coffee brown, hindwing clearly darker coloured (Fig. 10). Venation brown, in hindwing the veins and crossveins appear distinctly paler than the wing membrane, except at the wing base. Forewing with darker striation along the costal and subcostal fields; apical 1 / 4 of forewing obscurely paler, except for the extreme tip; base of forewing subhyaline. The apical 1 / 5 of the hindwing conspicuously darker brown; at the lower wing border the dark colour extends basad to half the wing length. Base of hindwing subhyaline to the level of the distal end of the quadrangle. Wings moderately broad, in hindwing the length/breadth ratio is 2.9–3.2. Reticulation sparse for the genus, best seen in the number of intercalary veins and density of crossveins in the area defined by CuP and the wing border (Fig. 14). Median space with 1–5 (usually 3) crossveins. Cubital space with 15–19 crossveins in forewing, 16–19 in hindwing. Quadrangle with 8–11 crossveins in forewing, 9–12 in hindwing. Antenodals (the first series) number 32–40 in forewing and 30–35 in hindwing.
Abdomen shining metallic blue throughout on dorsum and sides, with greenish tint on S 6–7. Underside (including the lower edges of tergites) uniformly dark, except for the sternites of the two basal and apical segments, which pale or partly pale. Appendages black, except the basal part of the inferiors which is pale on the underside; shaped as in Fig. 15. Penis as in Figs. 16–17.
Measurements (mm): abdomen + appendages 54.5–55; hind wing 38–40.5.
Description of female (Fig. 6). Colour pattern of head and thorax similar to the male. Legs as in male. Wings (Fig. 12) coffee brown, hindwing clearly darker coloured. The tip of forewing darkened. The apical part of hindwing darker; at the upper wing margin the darker coloration extends basad to the level of the nodus; at the lower wing margin the darker coloration extends slightly more basad; in the middle of the wing it extends to halfway between the nodus and pseudopterostigma. Veins and crossveins pale brown. White pseudopterostigma in both wings, covering 5–7 cells. Wings proportionally narrower than in male; in hindwing length/breadth ratio 3.2. At wing base the reticulation is denser than in male. Median space with 2–5 reticulated crossveins. Cubital space with 18–21 crossveins in forewing, 18–21 in hindwing. Quadrangle with 12–14 crossveins in forewing, 14–15 in hindwing. Antenodals (the first series) number 40–47 in forewing and 32–36 in hindwing.
Abdomen dark metallic green with brownish tint; a narrow pale band middorsally on S 8–10, on S 8 covering the apical 2 / 3; lower lateral side of S 8–10 brownish yellow, the same colour also at the apical end of S 7.
Measurements (mm): abdomen + appendages 50.5–53.5; hind wing 40.5–43.5.
Remarks on biology. In Tianmushan this species can be found on streams with rocky or sandy substrates, between 2–6 metres in width. We even found them near a waterfall. In fine days they always stay along the streams, where they can be quite conspicuous, occasionally displaying their brown wings with a slow wing clap after a short flight. On rainy days they can be found perching on low-lying vegetation in the shady forest beside the streams. Unfortunately no mating behaviour was observed, but it is anticipated that the males establish territories and fight. Records were made between late June and early August. In late June both fully mature and teneral individuals occurred simultaneously, so apparently the species is on the wing at least from mid June to late August. Other odonate species on the same streams included: Matrona basilaris Selys, Archineura incarnata (Karsch), Bayadera bidentata Needham, B. melanopteryx Ris, Philoganga robusta Navás, Periaeschna magdalena Martin, Chlorogomphus suzukii Oguma, and Macromia malleifera Lieftinck.
Distribution. Confirmed records are available from Zhejiang, Hunan and Guizhou. It is possible that the records of ‘ M. kricheldorffi ‘ from Guizhou (Mt Zhujia, Duyun and Chishui) and Hunan (Xiaoxi), presented in the unpublished MSc thesis by Zhou (2007) refer to M. corephaea, but the record of ‘ M. kricheldorffi ’ from Guangyuan in Sichuan may be M. oreades. Moreover, based on the colour photographs of specimens in Wang (2007, colour pl. 67), M. corephaea seems to occur also in Henan. Wang identified the figured specimens incorrectly as Matrona basilaris nigipectus (sic!) Selys. It remains to be seen whether all specimens reported as ‘ Matrona basilaris nigipectus ’ by Wang & al. (1990) from the following localities in Henan: “Sanmenxia, Lushi, Qihe forestry station”, “Luanchuan, Mt. Laojun”, “Neixiang, Getiaopa”, “Nanyang, Tongbai”, “Shuiliandong” and “Xinyang, Shangcheng, Jingangtai” are in fact M. corephaea.
He (2007, p. 162-163) includes four colour photos from unspecified localities in China identified as ' Matrona basilaris nigripectus Selys'. The middle photo on p. 162 appears to show either M. corephaea (more likely) or M.
oreades female, the other two photos on p. 162 show M. basilaris male and female, but the photo on p. 163 shows male of Atrocalopteryx atrata (Selys).