Holotype, adult with 9 pairs of legs, female (slide no. XZ-PA2015025) (SNHM), China, Tibet, Motuo county, Dexing town, extracted from soil samples in a broad-leaved forest, alt. 1100 m, 29°40'N, 95°26'E, 3-XI-2015, coll. Y. Bu & G. Yang. Paratypes, 2 adults, with 9 pairs of legs, females (slides no. XZ-PA2015019 (SNHM), XZ-PA2015026 (SEM)), 2 subadults, with 8 pairs of legs (slides no. XZ-PA2015027 (SNHM), XZ-PA2015031 (SEM)), same data as holotype.

From the Latin biconjugarus referring to the anal plate with two pairs of clavate appendages.

Decapauropus biconjugarus sp. n. is distinguished from the other species in the genus by the shape of the anal plate: subquadrate, with obvious U-shape and concave lateral margins; distal part with 4 posteriorly directed clavate appendages, dorsal ones thickest, straight, annulate, those protruding from sternal side shorter and thinner, straight, glabrous. Posterior part of the pygidial sternum evenly rounded.

Holotype length 0.6 mm (Fig. 2A).

Head (Figs 1B, 2E). Dorsal head setae short to moderately long, clavate, lateral ones cylindrical. Relative lengths of setae, 1^st row: a₁ = 10, a₂ = 8 (10); 2^nd row: a₁ = (9) 10, a₂ = 18 (19) a₃ = 14; 3^rd row: a₁ = 8 (10), a₂ = (10) 12; 4^th row: a₁ = 8, a₂ = (16) 18, a₃ = (18) 20, a₄ = (30) 32; lateral group setae l₁ =26 (27), l₂ = 22 (25) l₃ = 20 (30); the ratio a₁/a₁–a₁ in 1^st row 0.8, 2^nd row 0.4, 3^rd row 0.4 and 4^th row 0.4. Temporal organs oval in dorsal view, their length 1.4 times as long as their shortest distance apart. Head cuticle glabrous.

Antennae (Figs 1A, 2B, 2C). Antennal segment 4 with four cylindrical setae; relative lengths of setae: p = 100, p’ = (39.9) 41.4, p’’ = 62.5 (63.8), r = (26) 27.6; tergal seta p (1.2) 1.3 times as long as tergal branch t. The latter cylindrical, 2.2 (2.3) times as long as its greatest diameter and (1.6) 1.7 times as long as sternal branch s, which itself is 2.3 times as long as its greatest diameter. Seta q cylindrical, blunt, 1.3 times as long as s. F₃ very thin with small base segment. Relative lengths of flagella (base segments included) and base segments: F₁ = 100, bs₁ = 6; F₂ = 44.4, bs₂ = 4; F₃ =83.3, bs₃ = 5. F₁ 4.5 times as long as t, F₂ and F₃ 2.7 and 5.0 times as long as s respectively. Distal calyces small; F₁ and F₂ with fusiform flagella axes just below calyx. Distal calyces spherical; distal part of flagella axes fusiform. Globulus g 1.75 times as long as wide; about 12 bracts, capsule subspherical; width of g 0.67 of the greatest diameter of t. Antennae nearly glabrous.

Trunk. Setae on collum subcylindrical, striate, and appearing simple. Sublateral setae length 27 μm, 2.5 times as long as submedian setae (Figs 1C, 2D); sternite process triangular, pointed; appendages narrowing distally and with flat caps (Figs 1C, 2D). Setae on tergites thin, cylindrical; 4 + 4 setae on tergite I (Fig. 2 G), 6 + 6 on II–IV, 6 + 4 on V, 4 + 2 on VI. Tergites glabrous.

Bothriotricha. Relative lengths: T₁ = 100, T₂ = 126.7, T₃ = 106.7, T₄ =128.0, T₅ = 206.7. Axes simple, straight, in all but T₃ very thin; axes of T₃ thickened in distal half (Figs 1D, 2F). Pubescent hairs simple, short, thin, strongest on distal half of T₃.

Legs. Setae on coxa and trochanter of leg IX length 20 and 23 μm respectively, furcate with subcylindrical, annulate, blunt branches (Fig. 1E). Tarsus of leg IX long, 45 μm, tapering, 4.1 times as long as its greatest diameter (Fig. 1F). Proximal seta long, 14 μm, tapering, striate; distal seta 11 μm, tapering, striate; their lengths 0.35 and 0.30 of the tarsal length, respectively. Cuticle of tarsus glabrous.

Pygidum. Tergum (Figs 1G, 2H). Posterior margin evenly rounded but with small median triangular lobe between a₁ and st, the lobe granulated distally. Relative lengths of setae: a₁ = 100, a₂ = 82.4, a₃ = 117.6, st = 58.8. All setae subcylindrical, blunt, striate; st convergent; Distance a₁–a₁ 0.64 of length of a₁; distance a₁–a₂ 3.3 times as long as a₂–a₃; distance st–st 1.5 times as long as st and 1.4 times as long as distance a₁–a₁. Sternum (Figs 1H, 2I). Posterior margin evenly rounded and smooth between b₁. Relative lengths of setae (a₁ =100): b₁ = 235.3, b₂ = 82.4. All setae subcylindrical, blunt, striate. Distance b₁–b₁ 0.7 of length of b₁; distance b₁–b₂ 1.1 times as long as b₂.

Anal plate subquadrate, with obvious U shape concave lateral margins; distal part with four posteriorly directed clavate appendages, tergal ones thickest, straight, annulate, those protruding from sternal side shorter and thinner, straight, glabrous. Tergal and sternal appendages 0.9 and 0.5 times as long as plate respectively. Plate and sternum glabrous.

This new species seems to be a very close relative of D. bedosae Scheller from north-western Thailand (Scheller 1995) and D. cibodasensis Scheller from Singapore (Scheller 2007). They can be distinguished by the shape of the posterior part of the pygidial sternum (margin evenly rounded in the new species vs. straight in D. cibodasensis; with broad indentation in D. bedosae) and by the shape of the anal plate (plate short with medium appendages in D. biconjugarus; plate short with long appendages in D. cibodasensis; plate longer with sort appendages, especially the sternal ones in D. bedosae).

Holotype, adult with nine pairs of legs, female (slide no. XZ-PA2015007) (SNHM), China, Tibet, Linzhi City, Bomi county, Songzong town, extracted from soil samples in a broad-leaved forest, Alt. 3000 m, 29°76'N, 95°96'E, 7-XI-2015, coll. Y. Bu & G. Yang. Paratype, adult with 9 pairs of legs, female (slide no. XZ-PA2015009) (SNHM), same data as holotype.

The species is named after Tibet.

Decapauropus tibeticus sp. n. is distinguished from the other species in the genus by the shape of the anal plate bearing comma shaped appendages with pubescence. This in combination with st expanded and annulate distally is a very peculiar character for members of this genus.

Holotype length 0.72 mm (Fig. 4A), paratype length 0.77 mm.

Head (Figs 3B, 4E). Dorsal head setae short, blunt, densely annulate. Relative lengths of setae: 1^st row: a₁ = 10, a₂ = 12 (8.6); 2^nd row: a₁ = 12 (10), a₂ = 22 (14.3), a₃ = 18 (14.3); 3^rd row: a₁ = 16 (10), a₂ = 18 (12.9); 4^th row: a₁ = 18 (8.6), a₂ = 24 (17.1), a₃ = 26 (12.9), a₄ = 22.9 (?); lateral group setae l₁ = (20) 22.5, l₂ = (17) 20, l₃ = 14 (?). Ratio a₁/a₁‒a₁ in 1^st row 0.6, in 2^nd row 0.4, in 3^rd row 0.3, in 4^th row 0.75. Length of temporal organs 1.2 times as long as shortest interdistance. Head cuticle glabrous.

Antennae (Figs 3A, 4B). Antennal segment 4 with four cylindrical, annulate setae. Relative lengths of setae: p = 100, p’ = 46.2 (77.8), p” = 53.8 (66.7), r = 61.5 (88.9). Tergal seta p 1.3 (0.9 of) times as long as tergal branch t. The latter slender, cylindrical, 1.7 times as long as greatest diameter and 0.8 of sternal branch s which is 2.2 (1.5) times as long as greatest diameter; seta q 0.9 of sternal branch s. Relative lengths of flagella (base segment included) and base segments: F₁ = 100, bs₁ = 7.9 (8), F₂ = 36.5 (33.3), bs₂ = 13 (12), F₃ = 85.7 (73.3), bs₃ = 9.3 (9.1). F₁ 6.3 (7.5) times as long as t. F₂ and F₃ 1.8 (2.1) and 4.2 (4.6) times as long as s, respectively. Globulus g 1.8 (1.6) times as long as greatest diameter; width of g 0.7 (0.8) of greatest diameter of t.

Trunk. Setae on collum segment subcylindrical, simple, annulate (Figs 3C, 4D). Sublateral setae length 21 μm, 2.1 times as long as submedian setae (10 μm); sternite process thin, pointed anteriorly, with a little incision; appendages with low caps (Fig. 3C). Process and appendages with particles. Seta on tergites annulate, 4+4 on tergite I (Fig. 4F), 6+6 on II‒IV (Fig. 4G), 6+4 on V, 4+2 on VI (Fig. 4H).

Bothriotricha. Relative lengths: T₁ = 100, T₂ = 107.7 (107.1), T₃ = 92.3 (92.9), T₄ = 107.7 (107.1), T₅ = 123.1 (121.4). All but T₃ with very thin, simple straight axes and with short oblique pubescence. Axes of T₃ thickened in distal half. Pubescent hairs simple, short, thin, strongest on distal half of T₃ (Figs 3F, 4C).

Legs. Coxa and trochanter of leg IX with furcate setae, lengths 10 and 11 μm respectively, branches subcylindrical, blunt (Fig. 3G). Tarsus of leg IX short, 23 μm (Fig. 3D), somewhat tapering, 2.7 (2.9) times as long as greatest diameter; setae on similar appearance, thin, cylindrical, annulate, length 6‒7 μm, approx. 0.2 of length of tarsus.

Pygidum. Tergum (Fig. 3G). Posterior margin of pygidial tergum evenly rounded. Relative lengths of setae: a₁=100, a₂ = 86.7, a₃ = 113.3, st = 66.7. All setae but st blunt, annulate; st subcylindrical, straight, annulate, with a little expanding distally; Distance a₁‒a₁ 0.73 of a₁; distance a₁‒a₂ 2.7 times as long as a₂–a₃; distance st–st 1.7 times as long as st and st–st 1.3 times as long as distance a₁‒a₁. Sternum (Fig. 3H). Posterior margin of sternum evenly rounded. Relative lengths of setae (a₁=100): b₁ = 233.3 (187.5), b₂ = 80 (68.8). All setae cylindrical, annulate. Distance b₁‒b₁ 1.8 times as long as length of b₁; distance b₁‒b₂ 0.16 of length of b₂.

Anal plate subsquare, glabrous, width 0.9 of length, posterior margin with two short, comma shaped, pubescent appendages, appendages with a pair of little stubs that are almost half length of plate.

The species differs significantly from the other congeners. The comma shaped appendages of the anal plate with a pair of little stubs are characters unknown in other members of the genus.

Holotype, adult with nine pairs of legs, male (slide no. XZ-PA2015037) (SNHM), China, Tibet, Motuo county, Beibeng town, extracted from the soil samples in a broad-leaved forest, alt. 1500 m, 29°30'N, 95°38'E, 5-XI-2015, coll. Y. Bu & G. Yang.

From Latin quadrangulus meaning four angles and referring to the shape of the base of the anal plate.

Hemipauropus quadrangulus sp. n. is distinguished from the other species in the genus by the shape of the anal plate, which has a peculiar small Shuriken base and 6+6 setae on tergite IV.

Length. 0.85 mm (Fig. 6A).

Head (Fig. 5B). Tergal setae rather long, leaf-shaped, with short pubescence, lateral setae including a3 of 2^nd row and a4 of 4^th row, cylindrical, tapering in distal half, pointed. Relative lengths of setae, 1^st row: a₁ = ?, a₂ =10; 2^nd row: a₁ = ?, a₂ = ?; a₃ = 15; 3^rd row: a₁ = ?, a₂ = 10.7; 4^th row: a₁ = 11.4, a₂ = 12.9, a₃ = ?, a₄ = 10; lateral group setae: l₁ = 24.3, l₂ = 25.7, l₃ = 20. Ratio a₁/a₁–a₁ in 1^st to 3^rd row unknown, in 4^th row 0.9. Temporal organs oval in tergal view, length 1.4 of shortest interdistance; pistil absent. Head cuticle with very fine granules, temporal organs glabrous.

Antennae (Figs 5A, 6H). Setae on segments 1–3 folioform. Segment 4 with four setae, p and p’ subcylidrical, p” leaf-shaped, r very thin, p’ and p” striate; relative lengths of setae: p = 10, p’ = 9.3, p” = 3.3, r = 4. Tergal branch t somewhat fusiform, 3.8 times as long as greatest diameter and 0.95 of the length of sternal branch s; that branch 2.9 times as long as greatest diameter; anterodistal corner truncated. Seta q 1.3 times as long as seta p’ of segment 4, 0.95 of the length of s. Relative lengths of flagella (base segments included) and base segments: F₁ = 100, bs₁ = 17.3; F₂ = 46.7, bs₂ = 14.7; F₃ = 101.3, bs₃ = 14.7. F₁ 3.3 times as long as t, F₂ and F₃ 1.2 and 2.5 times as long as s respectively. Distal organ of F₁ and F₂ consisting of densely arranged pubescent bracts around sessile capsule, F₃ with flat calyx; flagella axes below distal organs not widened in F₁ and F₂, slightly in F₃. Globulus g pyriform, 0.2 of the length of s, diameter 0.8 of greatest diameter of t; 8–10 bracts; capsule subspherical. Antennae almost glabrous.

Trunk. Setae of collum segment broad, phylliform, pubescent, secondary branch rudimentary and inserted just below the middle; sublateral setae length 20 μm, 1.3 times as long as submedian setae; sternite process broad, pointed anteriorly; appendages two-parted with low caps. Process with pubescence and appendages glabrous (Figs 5C, 6B). Tergites indistinctly divided transversally, II–IV with reticular pattern on both sides of the dividing line, only posterior of that line on VI (Fig. 6C–G). Setae cylindrical, 4+4 setae on tergite I (Fig. 6C), 6+6 on II–V (Figs 6 D–G), 4 only on VI (Fig. 6G). Submedian posterior setae on VI 0.2 of inter-distance and 0.4 (–0.5) of the length of pygidial setae a₁. Tergites glabrous.

Bothriotricha. Relative lengths: T₁ = 100, T₂ = 104.8, T₃ = ?, T₄=104.8, T₅ = ?. Axes thin, simple, straight, pubescence hairs exceedingly short.

Genital papillae (Figs 5F, 6I). Longish, conical with narrowing and extended distal half, 1.6 times as long as wide, seta short, 0.3 of the length of papilla. Coxal seta of leg II as on leg I, length 10 μm (Fig. 6I).

Legs. Fairly long. Setae on coxa and trochanter of leg IX furcate, main branch leaf-shaped, secondary branch subcylindrical, blunt, 0.5 of the length of seta (Figs 5E, 6J). Tarsus of leg IX long, broad, 60 μm in length, 4.3 times as long as greatest diameter; proximal seta short, blunt, length 10 μm, with pubescence, distal seta shorter and blunt, length 9 μm, with pubescence. Proximal seta 0.2 of the length of tarsus, 2.5 times as long as distal seta. Cuticle of tarsus almost glabrous (Fig. 5D).

Pygidium. Tergum (Fig. 5G). Cuticle glabrous. Posterior margin smooth and round between st. Setae of very different lengths, a₁ leaf shaped, pubescent, a₂ subcylindrical, almost straight, a₃ thin, tapering, pointed, a₂ and a₃ glabrous. st very short, pointed, converging; relative lengths of setae: a₁ = 10, a₂ = 13.8, a₃ = 31.3, st = 6.3. Distance a₁–a₁ 1.6 times as long as a₁; distance st–st 3.0 times as long as st and 1.2 times as long as distance a₁–a₁. Sternum (Fig. 5H). Posterior margin with a little indention; b₁ blunt, striate distally. Relative lengths (pygidial a₁ = 10), b₁ = 27.8, 0.8 of their inter-distance.

Anal plate simple and glabrous, with a little base, the base like a Shuriken; posterior median forked part 5.8 times as long as broadest basal part.

This species resembles H. macropus Scheller, 2009 from the Philippines and H. clava Scheller, 2013 from Australia. They can be readily distinguished by the shape of the anal plate (with little Shuriken base in H. quadrangulus sp. n. vs. broad base and two lateral spines in both H. macropus and H. clava) and by the numbers of the setae on tergite IV (6+6 setae in H. quadrangulus sp. n. and H. clava vs. 6+4 setae in H. macropus).