Brevitubus ellipticus sp. nov. (a圆Sŝe)

Figs 2–3, 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.; HNU599 .

Paratypes. China • 1 ♀; same data as for holotype; HNU598 . • 2 ♂♂; same data as for holotype; Pingzhu Nature Reserve Station; 23°57'07"N, 110°16'21"E; 1148 m a.s.l.; 13 Oct. 2021; collected by the same collectors as for the holotype; HNU600 to 601 .

Etymology. The specific epithet is derived from the Latin word “ ellipticus ” meaning “elliptical”, referring to the shape of the spermathecae; adjective.

Diagnosis. This new species is similar to B. haitun (Liu, Xu & Yin, 2023) comb. nov. in having similar spermathecae, copulatory ducts and femoral apophysis, but can be distinguished by the presence of a distinct Vshaped anterior margin of epigyne (versus epigyne without a V-shaped anterior margin in B. haitun) in female (compare Fig. 3C–D with fig. 9C–D in Liu et al. 2023), and by RTA forming an about three-quarters circle, with a long and sharp distal end (in dorsal view) (versus RTA forming a half-circle, with a short and flat distal end, also with an additional triangular apophysis at the base in B. haitun) in male (compare Fig. 2C–F with fig. 8C–F in Liu et al. 2023).

Description. Male (holotype): total length 3.61, carapace 1.57 long, 1.22 wide; abdomen 1.82 long, 0.98 wide. Carapace nearly round, with black marginal bands. Cervical groove and radial furrow indistinct. Fovea dark red, longitudinal. AER and PER recurved. Eye sizes and interdistances: AME 0.08, ALE 0.09, PME 0.08, PLE 0.09, AME−AME 0.05, AME−ALE 0.02, PME−PME 0.09, PME−PLE 0.05, ALE−PLE 0.07, AME−PME 0.07, ALE−ALE 0.44, PLE−PLE 0.54. CH 0.10. Chelicera with 3 promarginal and 2 retromarginal teeth. MOA 0.20 long, anterior width 0.23, posterior width 0.29. Leg measurements: I 6.33 (1.57, 0.56, 2.02, 1.48, 0.70); II 5.22 (1.07, 0.51, 1.58, 1.25, 0.81); III 4.53 (1.05, 0.45, 1.04, 1.15, 0.84); IV 6.80 (1.67, 0.52, 1.59, 2.04, 0.98); Leg formula: 4123. Leg spination: Femur I pv1-1-1-1, II pv1-1-1; Tibia I v2-2-2-2-2-2-2-2-2, II v2-2-2-2-2-2-2-2; Metatarsus I v2-2-2-2, II pv1-1-1-1, rv1-1-1. Abdomen oval, dorsally with short transverse white strip close to posterior end, ventrally with 2 longitudinally light brown stripes, 1 black patch anterior to spinnerets, and 1 additional patch centrally (Figs 2A, 2B).

Palp. Femur with a distinct apophysis (Fig. 2D). RTA strong, modified, forming a half-circle-shaped bend in dorsal view, and with sharp distal end and finger-shaped basal apophysis (Fig. 2C); in prolateral view, both sharp distal end and finger-shaped basal apophysis red brown, highly sclerotized (Fig. 2D). Tegular apophysis triangular. Sperm duct distinct, U-shaped (about a three-quarter circle), occupying ~1/3 length of tegulum. Embolus small and short. Conductor membranous, longitudinally elongated and supporting base of embolus (Fig. 2E).

Female (paratype HUN600): total length 3.80; carapace 1.77 long, 1.49 wide; abdomen 1.93 long, 1.12 wide. Carapace yellowish-brown, with a chrysanthemum-petal-shaped pattern (but not very conspicuous) (Figs 3A, 3B). Cervical groove and radial furrow integrating into the pattern of carapace. Fovea dark red, longitudinal. AER and PER slightly recurved. Eye sizes and interdistances: AME 0.08, ALE 0.09, PME 0.09, PLE 0.10, AME−AME 0.02, AME−ALE 0.01, PME−PME 0.06, PME−PLE 0.03, ALE−PLE 0.07, AME−PME 0.07, ALE−ALE 0.45, PLE−PLE 0.56. CH 0.08. Chelicera with 3 promarginal and 2 retromarginal teeth. MOA 0.26 long, anterior width 0.23, posterior width 0.31. Leg measurements: I 6.59 (1.60, 0.58, 2.02, 1.54, 0.85); II 5.58 (1.33, 0.55, 1.58, 1.30, 0.82); III 4.68 (1.13, 0.54, 1.02, 1.21, 0.78); IV 6.99 (1.72, 0.54, 1.69, 2.08, 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 pv1-1-1-1-1-1-1, rv1-1-1-1-1-1; Metatarsus I v2-2-2-2, II pv1-1-1-1, rv1-1-1. Characteristics of abdomen resemble those of male, except for the absence of a ventral central patch in female.

Epigyne. Copulatory openings indistinct (Fig. 3C); copulatory ducts expanded sac-shaped (Fig. 3D); connecting tubes short, upright, parallel and close to each other (Fig. 3C). Spermathecae bean-shaped, obliquely and slightly elongating (Fig. 3D). Fertilization ducts almost upright, originating from anterior margin of spermathecae, roughly equal in length to connecting tubes (Fig. 3D).

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