Glyphiulus fortis sp. nov.

Figs 1A, 3–5

Type material. Holotype male, China: Guangxi Zhuang Autonomous Region, Bama County, Jiazhuan Town, Poyue Village, Baimo Cave, 24°17'58.33" N, 107°06'10.36" E, 331 m a.s.l., 29 May 2019, X.K. Jiang & H.M. Chen leg. Paratypes: 16 males, 16 females and 8 juveniles, same data as holotype .

Etymology. This specific name is derived from the Latin word fortis, meaning ‘strong, robust’ and refers to the shape of telopodites and coxosternal processes of the anterior gonopod, adjective.

Diagnosis. This species with contiguous processes on the coxosternum of the male first leg-pair belongs to the Glyphiulus javanicus -group, and it can be separated from other species in this group by (1) the crests on the collum being complete and developed, and the carinotaxic formula I–III + P + M (Figs 3A, 4A, B); (2) male legs I strongly degraded, two-segmented, distinctly shorter than the coxosternal process (Fig. 5A); (3) the coxite process of the anterior gonopod strong and extremely prolonged (Fig. 5C); (4) male femora VI and VII normal, without modifications. This species is very similar to G. impletus, but can be distinguished from the latter by the broader and stronger coxite process of the anterior gonopod.

Description. Body segments with 56–71p + 1–3a + T (holotype 71p + 1a + T). Body size of ca. 40–63 mm long and 2.0– 2.3 mm wide (holotype 63 and 2.3 mm, respectively). Color generally light yellowish brown (Fig. 1A).

Head. Each eye patch with 18–22 pigmented eyes arranged in 2–4 irregular linear rows (Fig. 3A). Antennae (Figs 3A, 4B) slender, densely setose. Antennomeres 1, 6–7 cylindrical, 2–5 clavate. Relative antennomere lengths 5≥3>4≥2≥6>1≥7. Labrum with four teeth anteromedially. Gnathochilarium with a separate promentum, polytrichous.

Collum. All crests complete and developed, carinotaxic formula I–III + P + M (Figs 3A, 4A, B).

Body rings. Postcollum constriction modest (Fig. 4A). Tegument smooth (Figs 4A–E). Metatergal strongly crested, carinotaxic formula 2/2+I/i+3/3+I/i+2/2 (Figs 3B–D, F, 4A–E). Ozoporiferous tubercles with rounded tip, higher than broad, larger than other tubercles (Figs 3B–D, F, 4A–D). Lateral crests strong (Figs 3B, D, 4B, D). Midbody rings round in cross-section (Fig. 3B).

Telson. Epiproct simple, with a rounded caudal ridge and a small dorsal tooth (Figs 3F, 4E). Paraprocts convex, oligotrichous (Figs 3E, 4F). Hypoproct crescent-shaped (Figs 3E, 4F).

Walking legs. Slender, distinctly longer than body width, with a fine accessory claw (Fig. 3B).

Male sexual characters. Male legs I strongly reduced, 2 segmented, with a pair of medial coxosternal hooked processes in contact medially (Fig. 5A). Femora VI and VII normal, without modification. Coxite of anterior gonopods (Fig. 5C) subtriangular, ridged medially, with 3 or 4 lines of microsetae anteriorly. Coxite processes strong and extremely prolonged, with round tip, obviously longer than telopodites. Telopodites located laterally, one-segmented, thick, with several distal setae and a field of microsetae at base. Coxite of posterior gonopods (Fig. 5D) brush-like mediolaterally. Flagella short, broad, zigzag-edged, situated at the tip of coxite lobe (Fig. 5B, D). Lateral margin of coxite with a field of microsetae.

Ecology. This species is cavernicolous and inhabits Baimo Cave (Fig. 1B). Since this species shows a degree of troglomorphic traits, like elongation of legs and antennae and general pallid coloration, this species seems to be a troglophile.

Distribution. Known only from the type locality.