Trichopeltis bellus, Liu, Weixin, Golovatch, Sergei & Tian, Mingyi, 2017

Liu, Weixin, Golovatch, Sergei & Tian, Mingyi, 2017, Three new cavernicolous species of the millipede genus Trichopeltis Pocock, 1894 from southern China (Diplopoda, Polydesmida, Cryptodesmidae), ZooKeys 710, pp. 1-14 : 2-4

Trichopeltis bellus sp. n. Figs 1, 2, 3

Type material.

Holotype> (SCAU), China, Yunnan Province, Qujing City, Luoping County, Machang Village, Shuiyuan Dong Cave, 24°49'33"N, 104°21'48"E, 1530 m, 18.VI.2015, leg. Mingyi Tian, Weixin Liu, Xinhui Wang & Mingruo Tang.

Paratypes.

2 + juv. (SCAU), same data as the holotype.

Etymology.

To emphasize the very pretty appearance of this species; adjective.

Diagnosis.

Differs from other species of the genus by the unusually elongate and densely setose gonopodal coxa. Superficially similar to T. intricatus sp. n., but distinguished from the latter in the longer tergal setae (Fig. 1A), and gonopodal femorite with a large, club-shaped, mesoventral lobe (Fig. 3). See also Key below.

Description.

Length of holotype ca. 16 mm, width of midbody pro- and metazonae 1.5 and 4.5 mm, respectively. Coloration in alcohol uniformly light yellow. Adults with 20 segments (Fig. 1). In width, head <collum <segment 2 <3 <4 <5 <7 16 <6 (Figs 1A, 2A); following segment 16, body rapidly tapering towards telson (Fig. 1A).

Head: vertex densely pilose and microgranulate, clypeus clearly smooth (Fig. 2B), epicranial suture superficial. Labrum with three teeth. Antennae short and clavate, reaching behind segment 2 when stretched dorsally; in length, antennomere 6> 3> 2> 5 = 4> 1> 7 (Fig. 2B).

Collum fan-shaped (Fig. 2A), incompletely covering the head from above, dorsal surface with six irregular transverse rows of small, round, setigerous tubercles (Fig. 2A). Marginal lobules on collum: 13+13 small, microvillose, setigerous, nearly sharp anteriorly and 6+6 similarly small, microvillose, but squarish laterally.

Mid-dorsal regions on segments 2 16 with five more or less regular, transverse rows of similarly small, setigerous tubercles, 6 8 + 6 8 per row (Fig. 2A). The tubercles extending onto paraterga, but each of the latter only with three or four irregular rows of similar tubercles (Fig. 1A). Following metaterga with 6 8 rows of smaller tubercles (Fig. 2E).

Paraterga very strongly developed (Figs 1 2), high, only slightly declivous, but never extending down below level of venter (Fig. 2C), each with 6 8 small, dentiform, lateral and 5 7 much larger, squarish caudolateral lobules, all evident, setigerous and microvillose (Figs 1 2). Caudolateral lobules on paraterga mostly oblong, relatively large, and well separated from one another (Figs 1 2). Caudolateral corner of paraterga projecting behind rear tergal margin only on segments 17 19 (Fig. 3E F).

Integument clearly microgranulate throughout (Fig. 1A), prozonae finely alveolated. Limbus regularly crenulated. Stricture between pro- and metazonae broad, shallow and finely microgranulated. Tergal setae simple, very long and subfiliform (Fig. 1A). Ozopores invisible, pore formula untraceable.

Epiproct tip sharp, with four spinnerets apically (Fig. 2F). Hypoproct subtrapeziform, 1+1 caudal setigerous papillae clearly separated (Fig. 2F).

Pleurosternal carinae clearly present on segment 2 alone. Sterna modestly setose, cross-impressions moderate, clearly broadened between> coxae 6, 7 and 9 (Figs 1B, 2D). Gonopod aperture rhomboid (Figs 1B, 2D).

Legs very long and slender, unmodified, produced beyond paratergal lateral margin (Figs 1B, 2C), about 1.8 times as long as midbody height.

Gonopods (Fig. 3) complex. Coxa subcylindrical, unusually long, and very densely setose on lateral side. Prefemora densely setose, with a few particularly long setae. Femorite composed of extremely strong mesoventral process (fp), the latter about as long as telopodite, slightly curved, club-shaped. Acropodite suberect, laterally with a smaller, parabasal, rounded process (p) supporting a still smaller lobe (a) apically. Acropodite with one evident apical lobe (l) and a few very small subapical lobules (lo). Seminal groove (sg) entirely mesal, terminating without pulvillus at lo, forming no distinct solenomere.

Remark.

Based on the unpigmented body and long legs, this species is probably a troglobite.