Nepalmatoiulus belousovi, Mikhaljova, 2023

Mikhaljova, Elena V., 2023, A contribution to the millipede fauna of China: descriptions of four new species of the genus Nepalmatoiulus Mauriès, 1983 from high-altitude areas of Yunnan Province (Diplopoda, Julida, Julidae), Zootaxa 5357 (2), pp. 285-300 : 292-296

Nepalmatoiulus belousovi sp. nov.

Figs 25–36

Material examined. Holotype: male ( ZMUM), China, Yunnan Province, Laojunshan watershed Yushi & Chongjiang r., 26°39´22´´ N, 99°41´3´´ E, H = 4020 m, 22.06. 2014, leg. I. Belousov, I. Kabak. Paratypes: 1male (dissected), 1 female (dissected) ( ZMUM), same data as for holotype .

Diagnosis. Differs from congeners mainly by the mesomeral process with an arcuate apical part and a median ledge (le in Fig. 36 ), by the relatively short velum couple with a medium-length solenomere not reaching the apex of mesomeral process and a promere distally very slightly expanded and apically relatively obliquely rounded.

Description. Male. Length in alcohol 34.0–35.0 mm, midbody vertical diameter about 2.5 mm, with 52(–1) (in holotype) and 53(–1) (in paratype) rings, excluding telson. Coloration in alcohol uniformly dark grey with brownish narrow transverse line on caudal margin of each metazonite. Legs and antennae dark brown. Head dark brown with light brown anterior part. Eyepatches black. Gnathochilarium marbled brown with yellow distal part. Apical portion of the marbled dark brown mandibular stipital lobe with yellow border.

Head smooth, 1+1 epicranial setae, 4 supralabral setae, not less than 28 labral setae (in paratype), and a group of tiny setae on forehead. Eye patches almost oval, composed of about 50 ommatidia (in paratype). Antennae medium-sized, rather slender and clavate. Length ratios of antennomeres 3–7 as 4.3:4.4:5.6:3.7:1, width ratios as 1.8:1.8:2.3:2.0:1. Antennomeres 5 and 6 with incomplete distodorsal corolla of sensilla basiconica. Mandibular stipites with subrectangular smooth lobes. Gnathochilarium: not less than 12 nonapical stipital setae; lamellae linguales each with not less than 5 setae arranged longitudinally.

Collum laterally with distinct lower striae of different length at posterior margin not reaching to anterior margin, dorsally with distinct short striae at posterior margin. A transverse row of very sparse setae at hind edge of collum.

Body rings circular. Prozona smooth except for ventral part with very indistinct obliquely located striae. Metazona with dense, regular, longitudinal striae reaching hind margin (21 or 22 striae in an approximate square with sides equal to metazonital length of a dorsal side of a midbody ring). Limbus straight, smooth (of Type 1 in Enghoff 1987). A transverse row of sparse, thin setae at hind edge of metazonites, setae gradually growing denser and longer toward telson. Ozopores small, lying behind suture between pro- and metazona without touching it. Caudal dorsal projection of telson straight and long, covered with setae and carrying at tip a claw-shaped process curved dorsally.

Preanal ring of telson covered with sparse, relatively long setae. Anal valves setose, their distal portions densely setose. Subanal scale densely setose, especially along caudal edge.

Legs relatively short and slender. Very delicately serrate ventral pads present on postfemur and tibia, starting from legs 2 ( Fig. 27 ); the pads somewhat decreasing in size towards telson. The hind most legs without ventral pads. Claw of all legs at base with a long (longer than claw) setiform accessory claw ventrally ( Fig. 26 ). Leg pair 1 forming a hook, the distal segment not touching basal segments (“Open hook” type in Enghoff 1987): coxa with one seta, postfemur with slightly scaly-rugose ventral surface, tip indistinctly wrinkly; distal segment without seta and tarsal remnant ( Fig. 25 ). Coxa 2 with one mesapical oral seta (o), a gland opening positioned in apical and axial position according to Enghoff (1987) ( Figs 27, 28 ; mesapical oral seta on the left is broken off). Penis almost pearshaped, about 1.3 × longer than wide ( Fig. 29 ). Ventral margin of body segment VII with lobes similar to figure 32 in Enghoff (1987).

Gonopods protruding. Anterior gonopod distally very slightly expanded, apically relatively obliquely rounded, distal margins of the apical excavation papillate, rudimentary telopodite without seta ( Figs 31, 34, 35 ). Flagellum enough long, slender, caudally covered with scales in the basal half; distal part densely covered with cuticular conical denticles throughout ( Figs 32, 33 ). Mesomeral process with median ledge (le) and slender, arcuate apical part bearing small subapical protrusion (p) located on mesal side ( Fig. 36 ). Apex (a) of the mesomeral process glabrous. Anterior surface of the mesomeral process with longitudinal subbasal deepening (not visible in Fig. 36 ). Velum (v) relatively short, with strongly sloped smooth margin, without a notch near the mesomeral process. Margin of accessory membrane (m) serrate. Solenomere (sl) medium-length (not reaching the apex of mesomeral process), spinose throughout.

Female. Length in alcohol about 37.0 mm, midbody vertical diameter about 3.0 mm, with 50(–1) rings, excluding telson. Vulva as in Fig. 30 .

Etymology. Honours Dr. I. A. Belousov, one of the collectors of this material. A noun in genitive.

Figures

FIGURES 36. Nepalmatoiulus belousovi sp. nov., male paratype (ZMUM). Opisthomere, mesal view. Abbreviations: a, apex; le, ledge; m, accessory membrane; p, protrusion; sl, solenomere; v, velum. Scale: 100 μm.

FIGURES 25–30. Nepalmatoiulus belousovi sp. nov., male (Figs 25–29) and female (Fig. 30) paratypes (ZMUM). 25. Leg pair 1, anterior view. 26. Claw 2, anterior view. 27. Leg pair 2, anterior view (mesapical oral seta on the left broken off). 28. Coxae 2, anterior view (mesapical oral seta on the left broken off). 29. Penis, posterior view. 30. Vulva, posterior view. Abbreviation: o, mesapical oral seta. Scales: 10 μm (Fig. 26), 30 μm (Fig. 28) 100 μm (Figs 25, 27, 29, 30).

FIGURES 31–35. Nepalmatoiulus belousovi sp. nov., male paratype (ZMUM). 31. Left promere, posterior view. 32. Flagellum. 33. Distal part of flagellum. 34. Distal part of left promere, posterior view. 35. Section of promere apex. Scales: 10 μm (Figs 33, 35), 20 μm (Fig. 34), 100 μm (Figs 31, 32).