Body length 12.4–19.1 mm, antennae composed of 20–22 articles, commonly 20 articles, 9–10 ocelli on each side of the head, arranged in three irregular rows, posterior two comparatively large ocelli; Tömösváry’s organ larger than the adjacent ocelli; commonly 2+2 forcipular coxosternal teeth, porodonts moderately slender, posterolateral to the lateral-most tooth, posterior angles of all tergites without triangular projections; 3–8 coxal pores, arranged in one row; female gonopods with 3+3 (few 3+2) moderately small coniform spurs, apical claw simple; male gonopods short and small, with three or four long setae on the terminal segment.

Figures 1–7. 

Lithobius (Ezembius) varioporus sp. nov., 1–2, 4, 7 holotype, male 1 habitus, dorsal view 2, 3 ocelli and Tömösváry’s organ (To), lateral view 4 forcipulae, ventral view 5, 6 paratype, female 5 posterior segments and gonopods, ventral view 6 gonopods, ventral view 7 posterior segments and gonopods, ventral view. Scale bars: 2 mm (1); 250 μm (2, 3); 500 μm (4–7).

Holotype : ♂ (Fig. 1) (EV1). Body length 19.1 mm, cephalic plate 1.8 mm long, 1.7 mm wide, Heiyagou Village, Longquanguan Town, Fuping County, Baoding City, Hebei Province, China, 38°57'03.77"N, 113°48'40.70"E, 1100 m, under litter of the forest floor in a mixed coniferous broad-leaved forest, 5 August 2014, leg. S. Pei, H. Ma. Paratypes [13♀♀, 19 ♂♂] (EV1): same data as holotype. Other material: 26 ♀♀, 32 ♂♂ (EV2) Liaodaobei, Longquanguan Town, Fuping County, Baoding City, Hebei Province, China, 38°50'50.12"N, 113°49'50.33"E, 1800 m, 5 August 2014, leg. S. Pei, H. Ma. 20♀♀, 21♂♂ (EV3) Wuyuezhai Mountain, Lingshou County, Shijiazhuang City, Hebei Province, China, 38°43'15.02"N, 114°08'32.62"E, 500 m, under litter of the forest floor in a mixed coniferous broad-leaved forest, 28 Sept 2014, leg. S. Pei, H. Ma.

Body length: 12.4–19.1 mm, cephalic plate 1.4–2.0 mm long, 1.4–1.8 mm wide.

Colour : antennal articles yellow-brown with blackish hue, the black gradually becomes lighter at the end of articles 6 and 7, distal-most article yellow-brown; and all tergites yellow-brown, TT 1, 3, 14, and 15 darker, pleural region pale grey with lavender hue, and sternites pale yellow-brown; basal and proximal parts of forcipules, forcipular coxosternite, SS 14 and 15 darker yellow-brown; all legs yellow-brown, distal tarsi darker.

Antennae : 20–22 articles, commonly 20+20 articles (Fig. 1), few specimens 20+21 or 20+22 articles; antennae article lengths are longer than wide except basal articles, which are equal to widths, distal-most article 2.9–3.2 times as long as wide; abundant setae on the antennal surface, less so on the basal articles, gradual increase in density of setae to ca. the fifth article, then more or less constant.

Cephalic plate smooth, convex, slightly longer than wide; tiny setae emerging from setal sockets scattered very sparsely over the whole surface; frontal marginal ridge with shallow anterior median furrow; short to long setae scattered along the marginal ridge of the cephalic plate; lateral marginal ridge discontinuous, posterior margin continuous, straight, wider than lateral marginal ridge, the middle of the posterior edge is very slightly concaved forward (Fig. 1). Nine to ten approximate oval ocelli on each side (Figs 2, 3), domed, translucent, usually darkly pigmented, situated in three irregular rows; the posterior two ocelli comparatively large; others subequal in size. Tömösváry’s organ situated at anterolateral margin of the cephalic plate, slightly smaller than the adjoining ocelli and lying well apart from them (Figs 2, 3).

Coxosternite subtrapezoidal (Fig. 1), anterior margin narrow, lateral margins slightly longer than medial margins; median diastema moderately deep, narrow U-shaped; anterior margin with 2+2 blunt triangular teeth; porodonts slender, lying posterolateral to and separated from the lateral-most tooth (Fig. 4); scattered long setae on the ventral side of coxosternite, longer setae near the dental margin.

All tergites smooth, without wrinkles, dorsum slightly convex; tiny setae emerging from setal sockets scattered sparsely over the entire surface, few long setae near the margin. Lateral marginal ridges of all tergites continuous. Posterior margin of TT 1, 3, and 5 feebly concave, posterior marginal ridges continuous, posterior margins of TT 7, 8, 10, 12, and 14 feebly concave, posterior marginal ridges discontinuous. Posterior angles of tergites generally rounded, without triangular projections. Miniscule setae scattered sparsely over the surface, two or three slightly thick and long setae on anterior and posterior angles of each tergite.

Sternites. Posterior side narrower than anterior side, generally inverted trapezoidal, smooth; setae emerging from setal sockets sparsely scattered on the surface and lateral margin, 3–5 long setae on the surface of the anterior part of each sternite, two or three comparatively long setae scattered sparsely on the surface of the posterior part of each sternite.

Legs robust, tarsal articulation ill-defined on legs 1–13, faint trace on ventral side, well-defined on legs 14 and 15; short to long setae sparsely scattered over the surface of prefemur, femur, tibia, and tarsus of all legs, with more setae on the tarsal surface; setae on dorsal and ventral surface of tarsus slightly longer than the anterior and posterior, one row of thicker setae regularly arranged on the medial ventral side of tibia of legs 1–13, with setae significantly reduced in legs 14 and 15, no thicker setae regularly arranged in one row on the medial ventral side of tibia. All legs with fairly long curved claws; legs 1–13 with anterior and posterior accessory spines; anterior accessory spines moderately long and slender, forming a moderately small angle with the claw, posterior accessory spines slightly more robust, forming a comparatively large angle with the claw, legs 14 and 15 only with small posterior accessory spines; legs 14 and 15 moderately thicker and longer than the anterior pairs in the female; In the female, tarsus 1 4.0–6.0 times as long as wide in legs 15, tarsus 2 ca. 73.1 %–77.3 % length of tarsus on legs 15; In the male, tarsus 1 3.3–7.3 times as long as wide in legs 15, tarsus 2 ca. 51.1 %–77.6 % length of tarsus on legs 15. Leg plectrotaxy provided in Table 1.

Coxal pores 3–8, round to slightly oval, in a row; in the female, 4554, 67(8)7(8)6, 5(6)765, 6(7)776, 66(7)65, in the male, 66(7)7(6)5(4), 565(6)3, coxal pore field set in a relatively shallow groove, the coxal pore-field fringe with a prominence; prominence with 10–15 short to moderately long setae sparsely scattered over the surface.

Female S 15 anterior margin broader than posterior, generally inverted trapezoidal, posteriomedially straight, colour usually yellow-brown; short to long sparse setae evenly scattered on surface; surface of the lateral sternal margin of genital segment well chitinised, posterior margin of genital sternite deeply concave between condyles of gonopods, except for a small, median approximately rhombic-shaped bulge; relatively long setae sparsely scattered over ventral surface of the genital segment. Gonopods (Figs 5, 6): first article fairly broad, bearing 22–26 moderately long setae, arranged in five irregular rows; generally with 3+3 (3+2 in only two specimens) moderately long and slender, coniform spurs, inner spur slightly smaller than the outer, dorsolateral setae absent; second article with 12–16 long setae, arranged in three irregular rows, 9–12 stout setae on the dorsal side; third article with five or six comparatively long setae, arranged in two irregular rows, four or five stout setae on the dorsal side; third article with a simple broad apical claw (Figs 5, 6).

Male S 15 posterior margin narrower than anterior, posteriomedially straight, sparsely covered with long setae on the surface; sternite of genital segment smaller than in female, usually well sclerotised, posterior margin deeply concave between the gonopods, without median bulge; long setae sparsely scattered on the ventral surface of the genital segment, fringed with longer setae along the posterior margin; gonopods short, appearing as a small hemispherical bulge, with three or four long setae, apically slightly sclerotised (Fig. 7).

The specimens studied here were collected from a mixed coniferous broad-leaved forest at ca. 500–1800 m above sea level, in moderately moist habitats under roadside stones and litter of the forest floor.

The specific epithet varioporus refers to the coxal pore numbers varying considerably from three to eight.

The new species is morphologically close to L. (E.) laevidentata Pei, Ma, Hou, Zhu & Gai, 2015 and to L. (E.) tetraspinus Pei, Lu, Liu, Hou & Ma, 2018, both from the Xinjiang Uygur Autonomous Region, China, with which it shares 20–22 antennal articles, 9–10 ocelli arranged in three irregular rows, the posterior two ocelli comparatively large, 3+3 spurs on female gonopods, no anterior accessory spines on legs 15.

However, the new species can be easily distinguished from L. (E.) laevidentata by the size of the Tömösváry’s organ, slightly smaller than the adjoining ocelli, rather than subequal to the largest ocellus as in L. (E.) laevidentata. The new species has no secondary sexual modifications on the male 15 tibia compared to L. (E.) laevidentata, in which a distinct and shallow dorsal furrow is present on the same leg; moreover, in the new species legs 14 and 15 bears a small accessory spines only on the posterior side vs. both anterior and posterior accessory spines are present on legs 14, and only with posterior accessory spines present on legs 15 in L. (E.) laevidentata.

The new species can be easily distinguished from L. (E.) tetraspinus by the Tömösváry’s organ, slightly smaller than the adjoining ocelli in contrast to subequal in size to adjoining ocelli in L. (E.) tetraspinus. Moreover, the new species has no secondary sexual modifications on the leg 15 male tibia vs. the dorsal sulci on the femur in L. (E.) tetraspinus. In the new species, legs 14 and 15 bear small accessory spines only in the posterior side instead of both anterior and posterior accessory spines present on legs 14, and lacking accessory spines on legs 15 in L. (E.) tetraspinus. The new species must be also easily distinguished from the other Lithobius (Ezembius) species to date known from China by the coxal pore number, varying considerably from three to eight, not only among specimens, but also in the same individual.

To assist in the identification of the Lithobius species of the subgenus Ezembius from China, the main morphological characters based on adult specimens are presented in Table 3.