Brevitubus lunatus sp. nov. (šnSŝe)

Figs 4, 8

Type material. China • ♂ holotype; Guangxi, Laibin City, Jinxiu Yao Autonomous County, Shengtangshan Scenic Area; 23°58'03"N, 110°06'31"E; 1523 m a.s.l.; 11 Oct. 2021; A.L. He, J.X. Liu, Z.G. Huang, R.R. Liao, Q. Li, X.M. Yang, Y.L. Wen, Z. Ye, and Y. Liu leg.; HNU605 .

Etymology. The species epithet is the Latin word, “ lunatus ”, meaning “crescent-shaped”, in reference to the shape of the retrolateral tibial apophysis; adjective.

Diagnosis. Male of the new species is similar to that of B. subpinglong sp. nov. in having a U-shaped sperm duct, palm-shaped membranous conductor, and short and small embolus (compare Fig. 4 C−F with Fig. 7 C−F), but it can be distinguished by the shape of RTA with an additional branch besides a relatively short distal end in the new species, while RTA with a long distal end and without any additional branch in B. subpinglong sp. nov. (compare Fig. 4 C−F with Fig. 7 C−F).

Description. Male (holotype): total length 3.49, carapace 1.57 long, 1.36 wide; abdomen 1.83 long, 1.08wide. Carapace brown, with a conspicuous chrysanthemum-petal-shaped pattern (Fig. 4A). Cervical groove and radial furrow integrating into the pattern of carapace. Fovea dark red, longitudinal. AER and PER recurved. Eye sizes and interdistances: AME 0.08, ALE 0.09, PME 0.10, PLE 0.10, AME−AME 0.03, AME−ALE 0.01, PME−PME 0.08, PME−PLE 0.04, ALE−PLE 0.09, AME−PME 0.07, ALE−ALE 0.40, PLE−PLE 0.57. CH 0.06. Chelicera with 3 promarginal and 2 retromarginal teeth. MOA 0.22 long, anterior width 0.22, posterior width 0.28. Leg measurements: I 6.25 (1.48, 0.52, 1.90, 1.48, 0.87); II 5.00 (1.10, 0.47, 1.45, 1.15, 0.83); III 4.39 (1.07, 0.35, 1.04, 1.19, 0.74); IV 6.63 (1.70, 0.47, 1.68, 1.82, 0.96); Leg formula: 4123. Leg spination: Femur I pv1-1-1-1, II pv1-1-1; Tibia I v2-2-2- 2-2-2-2, II v2-2-2-2-2-2; Metatarsus I v2-2-2-2, II pv1-1-1-1, rv1-1-1. Abdomen oval. Dorsum almost black except for a short white stripe located at the posterior end (Fig. 4A). Venter light-yellow, with 2 black longitudinal stripes and 1 black patch anterior to spinnerets, and with 1 additional light brown patch centrally (Fig. 4B).

Palp. Femur with a distinct protrusion (Fig. 4D). RTA very strong in retrolateral view (Fig. 4F), with two apices in prolateral view (Fig. 4D), and with a sharp distal end and a basal apophysis with two tiny apices in dorsal view (Fig. 4C). Tegular apophysis triangular. Sperm duct distinct, U-shaped (forming about a three-quarter circle), occupying ~1/3 length of tegulum. Embolus small and short. Conductor membranous, longitudinally elongated and supporting the base of embolus (Fig. 4E).

Distribution. Known only from the type locality in Guangxi, China (Fig. 8).

Note. Although DNA sequences could not be successfully obtained for this new species, its morphological characteristics strongly support its placement within the new genus.