Kronopolites serratus Nguyen, Vu, Phung, Tran & Le, 2025, sp. nov.

Kronopolites serratus sp. nov. Figs 9, 10, 11 Material examined. Holotype: Vietnam • 1 male; Lao Cai Province, Hoang Lien National Park, Thac Bac waterfall; 22.36350°E, 103.77754°E; 1,950 m a. s. l.; regenerated forest; 28 November 2005; Anh D. Nguyen leg.; IEBR-Myr 109. Diagnosis. The new species is similar to K. montanus Golovatch, 2009, but differs in the following characters: gonopod process a curved, serrated, acuminate leaf-shaped, as long as distally serrated, ribbon-shaped process b. Description. Size: length 32.01 mm, width of midbody pro- and metazona 2.67 mm and 3.67 mm, respectively. Colouration (Fig. 9): almost uniformly brownish yellow after long preservation in ethanol. Head (Fig. 9 A – C): Clypeolabral region and vertex densely setose, epicranial suture distinct. Antennae claviform, moderately long (Fig. 9 A – C), extending behind body segment 3 when stretched laterally; antennomere 2 = 3 = 4> 5> 6> 7 = 1, antennomere 7 with four conical sensories. Collum: traces of setae hardly seen; lateral incisions absent; caudal corner of paraterga very broadly rounded, declined ventrad, produced behind rear tergal margin (Fig. 9 A, B). Body rings: In width, segment 4 <3 <head <5 <segment 2 <collum <6–17, thereafter body gently and gradually tapering. Tegument (Fig. 9 A – E) smooth and shining, prozonae finely shagreened; surface below paraterga finely rugulose. Tergal setae all broken, traces hardly seen. Axial line visible, especially on midbody tergites. Transverse sulcus usually distinct (Fig. 9 A), slightly incomplete on body rings 4 and 19, complete on metaterga 5–18, narrow, line – shaped, shallow, reaching bases of paraterga. Stricture between pro – and metazonae evident, broad and deep, striolated at bottom down to base of paraterga (Fig. 9 D). Pleurosternal carinae complete crests on body rings 2–7; thereafter, increasingly strongly reduced until body ring 17. Paraterga strongly developed (Fig. 9 A, D), lying below dorsum; anterior edge broadly rounded and narrowly bordered, fused to callus; caudal corner very narrowly rounded; lateral edge without incisions; posterior edge nearly straight. Calluses on paraterga narrow, delimited by a sulcus both dorsally and ventrally. Ozopores (Fig. 9 D, E) evident, lateral, lying in an ovoid groove at ~ 1 / 4 in front of posterior edge of metaterga. Telson: damaged. Sterna: densely setose, without modifications (Fig. 9 C, F). Legs: rather long and slender, midbody ones ~ 1.2–1.3 times as long as body height; prefemora without modifications, tarsal brushes present only on pregonopodal legs Gonopods (Figs 10, 11) a typical Kronopolites species; coxite (co) stout, subcylindrical, sparsely setose distoventrally. Prefemur (pref) densely setose, ~ 1 / 3 as long as femorite + postfemoral part. Femorite somewhat stout, evidently grooved mesally, demarcated from postfemoral region by a distinct oblique sulcus laterally. Lamina l present, producing into a small spine z distally; process a leaf-shaped, mesal margin serrated, clearly shorter than distally-serrated, ribbon-shaped process b; solenophore well developed, bipartite, longer than a short flagelliform solenomere which parly sheathed by solenophore. Remarks. Although the new species is described based on only a male, its gonopod distinctly differs from that of K. montanus in gonopod process a being curved, serrated, acuminate leaf-shaped, as long as distally serrated, ribbon-shaped process b. Both species are also found in Hoang Lien National Park at the high elevation of more than 1,900 m a. s. l. Etymology. Serratus, an adjective epithet, is used to emphasise the serrated process a and b of the gonopod.