Glyphiulus xiniudong Zhao & Liu sp. nov.

Figs 5D, 10, 11

Type material.

Holotype ♂ (SCAU G78), China, Guangxi Zhuang Autonomous Region, Laibin City, Wuxuan County, Cave Xiniu Dong, 23°33'N, 109°32'55"E, 100 m alt., 2021-I-15, leg. Tian Mingyi, Liu Weixin & Zhao Yi. Paratypes: 4 ♂, 30 ♀ (SCAU G78), same data as the holotype.

Etymology.

To emphasise the provenance of this species from the “Xiniu” Cave, in Chinese meaning “rhinoceros”; noun in apposition.

Diagnosis.

Differs from congeners of the Glyphiulus formosus -group by the metazonae with an obvious, corrugate, carved texture and by the leg claw with a rather large accessory spine, coupled with a long subtriangular coxosternum of the anterior gonopod, the latter process being narrow and digitiform. Based on molecular evidence, G. xiniudong Zhao & Liu, sp. nov. differs from all other Glyphiulus species analysed in a> 14.7% uncorrected p-distance of the COI barcoding gene.

Description.

Length ca. 28.0-31.0 (♂) or 26.0-41.0 mm (♀), mid-body rings round in cross-section, their width and height similar, 1.1-1.3 (♂) or 1.2-1.8 mm (♀). Body with 42-54 (♂) or 45-64 (♀) podous + 0-3 apodous rings + telson. Colouration purple-brownish, legs almost transparent (Fig. 5D).

Head surface smooth. Labrum with four teeth anteromedially. Ocellaria blackish, with 9-13 ommatidia arranged in 1-2 irregular linear rows (Figs 10B, 11A). Antennae short, slightly clavate, reaching back to caudal margin of ring 2; in length, antennomeres 5> 3> 4 ≈ 2> 6> 1> 7. Antennomeres 5-7 each with a distodorsal field or corolla of bacilliform sensilla (sensory bacilli). Antennomere 7 with four sensory cones (Fig. 11B). Gnathochilarium with a separate promentum, polytrichous on promentum and mentum, lamellae linguales each with 6-7 setae (Fig. 11B). Mandible not dissected.

Collum: crests complete and evident; carinotaxy formula I-III+P+M (Figs 10A, 11A). Following metaterga strongly crested; carinotaxy formula 2/2+I/i+3/3 (Fig. 10). Ozoporiferous tubercles very large, coniform. Prozonae delicately alveolate-areolate, fine longitudinal striations in front of stricture. Metazonae with an obvious, corrugate, carved texture (Fig. 10). Rings 2 and 3 with long pleural flaps.

Epiproct simple, caudal edge uneven, with an obvious central tubercle dorsally (Fig. 10E). Paraprocts regularly convex, each with several irregular rows of setae. Hypoproct transversely bean-shaped, with 4+4 small setae (Fig. 10F).

Legs short, about as long as mid-body height; claw with a relatively large accessory spine at base, about half as long as claw (Fig. 11C). ♂ legs 1 very strongly reduced, represented by a sternum showing a pair of small, more slender, fused, paramedian, subunciform prongs directed forward, with about 7-9+7-9 long setae at base; flanked by strongly separated, rudimentary, 1-segmented leg vestiges, with some setae (Fig. 11D). ♂ legs 2 slightly hypertrophied, coxae large; penes rather small, much shorter than coxae, oblong-subtrapeziform, each with three strong setae distolaterally (Fig. 11E). ♂ legs 3 modified through coxae being especially slender and elongate. ♂ femora 6 and 7 normal, neither modifications.

Anterior gonopods (Fig. 11G) with a long subtriangular coxosternum with about 9-11 microsetae near distal margin; apicomesal process of coxite very high, rather narrow and digitiform, modestly curved inwards. Telopodite very large, stout and coiled, 1-segmented, lateral in position, much higher than lateral corner of coxite, with a field of six microspinules at base and 6-7 strong setae apically.

Posterior gonopods (Figs 11H, I) compact. Coxite subquadrate, with a circular field of about 10-15 basolateral microspinules in frontal view; with a field of 19 median microspinules and an apicolateral very strong and long seta in caudal view; apical and mesal parts of coxite with dense, strong and curved setae. Lamelliform lobe membranous, with a rather small, spine-like flagellum.

Vulvae very simple, bare, modestly emarginate medially (Fig. 11F).

Remark.

In the absence of direct troglomorphic traits, this species can only be considered as troglophilic at most.