Taxonomic studies on the sac spider genus Clubiona (Araneae, Clubionidae) from Xishuangbanna Rainforest, China Author Zhang, Jianshuang School of Life Sciences Author Yu, Hao Guizhou Normal University, Guiyang, Guizhou, China insect1986@126.com Author Li, Shuqiang https://orcid.org/0000-0002-3290-5416 School of Biological Sciences, Guizhou Education University, Guiyang, Guizhou, China lisq@ioz.ac.cn text ZooKeys 2021 2021-04-26 1034 1 163 http://dx.doi.org/10.3897/zookeys.1034.59413 journal article http://dx.doi.org/10.3897/zookeys.1034.59413 1313-2970-1034-1 A2937A0DFF04468FB2DB6AC4D68ED997 2DB5C14D37835632AB3585A3AECC3B1C Clubiona tixing Yu & Li sp. nov. Figs 18 , 73D , 81D , 89D Holotype ♀ (IZCAS-Ar 34750), China: Yunnan Province: Xishuangbanna: Jinghong City: Nabanhe Natural Reserve, Mandian Waterfall, monsoon forest, 22°7.845'N , 100°39.749'E , ca. 736 m, 22.VIII.2012, G. Zheng leg. Etymology. The specific name is derived from the Chinese pinyin tī xing , which means 'trapezoid' , referring to the trapezoidal atrium; noun in apposition. Diagnosis. Females of this species resemble those of C. zhangmuensis ( Zhang et al. 2007 : 38, figs 7-8) in having a similar atrium and endogyne but can be recognised by the presence of an atrial membrane (Figs 18A-C , 73D , 81D ) (vs. absent; Zhang et al. 2007 : 38, fig. 7). Description. Female. Holotype (Fig. 18F, G ): Total length 6.62; carapace 2.80 long, 2.02 wide; opisthosoma 3.82 long, 2.28 wide. Carapace brown in alcohol, uniformly coloured, without distinct pattern, ocular region distinctly narrowed, cervical groove and radial grooves indistinct; tegument smooth, clothed with short setae. Eyes: in dorsal view, both AER and PER almost straight, the former narrower than the latter. Eye sizes and interdistances: AME 0.14, ALE 0.15, PME 0.14, PLE 0.12, AME-AME 0.12, AME-ALE 0.13, PME-PME 0.39, PME-PLE 0.24, MOQL 0.43, MOQA 0.41, MOQP 0.67. Chelicerae robust and dark brown, with five promarginal and three retromarginal teeth. Sternum yellowish brown, darker marginally, 1.63 long, 1.00 wide. Labium and endites coloured as carapace. Legs uniformly yellowish white. Leg measurements: I - (1.71, 2.25, -, -), II - (1.78, 2.42, -, -), III - (1.60, 1.88, -, -), IV - (2.11, 2.55, 1.17, -). Abdomen elongate-oval, uniformly pale brown, with numerous brown spots; dorsally with a lengthwise white heart mark, reaching posterior half, with two pairs of muscle depressions located at lateral part of heart mark; venter medially with four longitudinal dotted lines. Epigyne (Figs 18A-E , 73D , 81D , 89D ). Epigynal plate distinctly wider than long, margin not rebordered, spermathecae and bursae are indistinctly visible through epigynal plate in ventral view. Atrium large, more or less rectangular or trapezoidal, ca. 1.3 x wider than long, ca. 1/3 of epigyne length, with tongue-shaped membrane on anterior margin, posterior atrial border not delimited. Copulatory openings indistinct, located at anterolateral atrial borders. Copulatory ducts short, bent dorsally and ascend obliquely to connect with bursae. Spermathecae convoluted, anteriorly situated, spermathecal heads thick. Bursae reniform, close together, ca. 1.6 x longer than wide, surface translucent and wrinkled. Male. Unknown. Distribution. Known only from the type locality, Xishuangbanna, Yunnan, China.