Yunguirius parvus Wei & Liu sp. nov. Figs 2, 3, 10 Type material. Holotype ♀ (HBU-WM-24-001), 1 ♀ paratype (HBU-WM-24-002): China: Yunnan Province, Honghe Hani and Yi Autonomous, Gejiu County, Gejia Forest Park, 23.3893 ° N, 103.1254 ° E, elevation: 2045 m, 23. VIII. 2020, M. Wei leg. Etymology. The specific epithet is taken from the Latin word parvus, meaning “ small ”, referring to the relatively small body type of new species; an adjective. Diagnosis. The females of Yunguirius parvus sp. nov. resemble those of Y. duoge in 1) the atrium is subrounded with a complete anterior margin (Fig. 2 A; fig. 2 A in Li et al. 2023); 2) the openings of the copulatory ducts are wide, approximately half the circumference of the atrium (Fig. 2 B; fig. 2 B in Li et al. 2023); 3) the blind sacs of the copulatory ducts are extremely short, symmetrical, and separate (Fig. 2 B; fig. 2 B in Li et al. 2023). In other Yunguirius species, the atrium is non-subrounded (except in Y. terebratus) with an incomplete anterior margin (Figs 1 A, 4 A, 6 A, 8 A; fig. 245 A in Zhu et al. 2017; figs 3 A, 4 A in Li et al. 2023), the copulatory openings are equal to or less than the length of the lateral margin of the atrium, and the blind sacs are asymmetrical and overlapping (Figs 1 B, 4 B, 6 B, 8 B; fig. 245 B in Zhu et al. 2017; figs 3 B, 4 B in Li et al. 2023). However, Y. parvus sp. nov. can be differentiated from Y. duoge by 1) the absence of the fold (Fig. 2 A), versus being present in the latter (Fig. 2 A in Li et al. 2023); 2) the blind sac is shorter than the spermathecal stalk (Fig. 2 B), versus being longer in the latter (Fig. 2 B in Li et al. 2023); 3) the spermathecal stalk has a conch-shaped distal tip (Fig. 2 B), versus being nearly round in the latter (Fig. 2 B in Li et al. 2023). Description. Female (holotype) (Fig. 3). Carapace reddish brown. Cervical and radial groove distinct. Cephalic region moderately raised and wide, lateral margin with distinct furrows. Chelicerae with 3 promarginal teeth and 2 retromarginal teeth, condyle red. Sternum longer than wide. Abdomen pale yellow, with 5 chevron-shaped patterns, covered by hairs. Legs red. Total length 10.41. Carapace 5.85 long, 3.54 wide, cephalic region 3.12 wide. Abdomen 4.69 long, 3.10 wide. Eye size and interdistance: AME 0.19, ALE 0.23, PME 0.22, PLE 0.25; AME – AME 0.09, AME – ALE 0.14, AME – PME 0.09, ALE – PLE 0.05, PME – PME 0.06, PME – PLE 0.32. Leg measurements: Leg I 14.02 (1.80, 0.70, 3.53, 1.63, 2.78, 2.46, 1.39), leg II 12.40 (1.52, 0.69, 3.04, 1.48, 2.44, 2.23, 1.33), leg III 10.35 (1.38, 0.67, 2.43, 1.32, 1.68, 1.95, 1.08), leg IV 14.42 (1.66, 0.61, 3.50, 1.59, 2.91, 2.84, 1.41). Epigyne (Fig. 2). Epigynal teeth absent. Atrium centrally situated, subrounded, anterior margin complete. Epigynal sclerite small. Hoods weak, vertically oriented, situated laterally. Fold absent. Copulatory ducts openings broad, subequal to ½ the circumference of atrium, laterally originated, blind sacs short, symmetric, and untouched. Spermathecal bases consisted of 2 spherical chambers, spermathecal stalks long, with distal tips conch-shaped, spermathecal heads anteriorly originated, long and sclerotized. Fertilization ducts posteriorly situated. Male. Unknown. Distribution. China (Yunnan).

Published as part of Wei, Mian, Liu, Jie & Wang, Kai, 2024, Four new species of the genus Yunguirius (Araneae, Agelenidae) from China, pp. 1-15 in ZooKeys 1211 on pages 1-15, DOI: 10.3897/zookeys.1211.126487