Nepalmatoiulus jianchuanensis, Mikhaljova, 2024

Mikhaljova, Elena V., 2024, New species and new records of millipedes of the genera Nepalmatoiulus Mauriès, 1983 and Anaulaciulus Pocock, 1895 (Diplopoda, Julida, Julidae) from mainland China, Zootaxa 5447 (4), pp. 496-512 : 500

Nepalmatoiulus jianchuanensis sp.nov.

Figs 10–20

Material examined. Holotype: 1 male ( ZMUM), China, Yunnan Province, NW of Jianchuan , 12.4 km WNW Shuanghecun, 26°37'41" N, 99°45'34" E, H = 3270 m, 17.05. 2016, leg. I. Kabak, G. Davidian. Paratype: 1 female ( ZMUM), same data as for holotype .

Diagnosis. Differs from Chinese congeners mainly by the combination of: slender opisthomere without a velum notch near apex of mesomeral process; broad setose solenomere with short subapical branch spinose arteriorly; apically strongly obliquely rounded promere. Similar to Nepalmatoiulus arcuatus Mikhaljova, 2023b and N. lancangensis sp. nov. in the general configuration of gonopods, but differs from both by specific characters (see Remarks below and Remarks to N. lancangensis sp. nov.).

Description. Male. Length in alcohol about 22.0 mm, midbody vertical diameter about 1.9 mm, with 51(- 2) rings, excluding telson. Coloration in alcohol brown-gray, with a broad dorsal light longitudinal stripe.Venter including basal parts of legs beige. Distal parts of legs marbled dark brown. Antennae dark brown, eyes black.

Head smooth, 2 epicranial setae, 4 supralabral setae; at least 26 labral setae. Eye patch almost oval, composed of at least 40 ommatidia in holotype. Antennae medium-sized, rather slender and clavate. Antennomeres 5 and 6 with incomplete distodorsal corolla of sensilla basiconica. Mandibular stipites with oval smooth lobes. Gnathochilarium with at least 10 nonapical stipital setae; lamellae linguales each with 6–7 setae arranged longitudinally. Collum laterally with distinct striae of different lengths at posterior margin, the first of which (the longest striae) reaching to anterior margin, dorsally with distinct short striae at posterior margin. A transverse row of very sparse thin setae at hind edge of collum.

Body rings circular. Metazona with dense, regular, longitudinal striae reaching hind margin (15–16 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. Telson with caudal dorsal projection straight and long, covered with setae and carrying at tip a claw-shaped process curved dorsally. Preanal ring, anal valves, and subanal scale densely setose.

Legs relatively short and slender. Very delicately serrate ventral pads present on postfemur and tibia, starting from legs 2. Claw of all legs at base with a setiform accessory claw ventrally, accessory claw relatively short (equal to claw length) in the anterior body part and very short (shorter than claw) in the hind most legs. Leg pair 1 forming hook, the distal podomere not coming into close contact with the basal podomeres (“open hook” type in Enghoff 1987); postfemur with inflated scaly-rugose ventral surface, tip indistinctly wrinkled, coxa with one seta, distal podomere without lateral seta and seta tarsal remnant ( Fig. 14 ). Coxa 2 with one long mesapical oral seta anteriorly ( Fig. 12 ) and a shorter one posteriorly ( Fig. 10 ), gland opening positioned in apical and axial position sensu Enghoff (1987). Penis subtrapezoidal, about 1.9 times longer than wide ( Fig. 11 ).

Gonopods relatively strongly protruding. Anterior gonopod flattened, with parallel margins, apically strongly obliquely rounded, in posterior view apically excavated for accommodation of mesomeral process, distal margins of the excavation papillate, rudimentary telopodite with seta ( Figs 16, 18 ). Flagellum slender, of medium length, caudally covered with cuticular conical spikes ( Figs 13, 17 ). Opisthomere slender ( Figs 19–20 ). Mesomeral process slightly arched forward, its apex covered with papillae. Margin of velum smooth, arcuate, without a notch near the mesomeral process (in Fig. 20 the opisthomere is slightly turned back, as a result, the mesomeral process protrudes forward and hides the absence of a notch on the margin of velum). Solenomere relatively short, with dense long thin spines basally and spinose arteriorly.

Female. Length in alcohol about 24.0 mm, midbody vertical diameter about 2.1 mm, with 48(-2) rings, excluding telson. Vulva as in Fig. 15 .

Etymology. The specific epithet refers to the type locality, Jianchuan. Adjective.

Remarks. Nepalmatoiulus jianchuanensis sp. nov. differs from N. arcuatus mainly by the smaller body length (about 22.0 mm) and larger midbody vertical diameter (about 1.9 mm) (vs. length—about 29.0 mm, midbody vertical diameter—about 1.5 mm in N. arcuatus ), relatively short and broad solenomere (vs. relatively long and slender in N. arcuatus ), by the distal podomere of male leg 1 without seta laterally (vs. with one seta laterally in N. arcuatus ), by the subtrapezoid penis (vs. like an hourglass figure penis in N. arcuatus ).

Figures

FIGURES 10–18. Nepalmatoiulus jianchuanensis sp. nov., male holotype and female (Fig. 15) paratype (ZMUM). 10. Coxa 2, posterior view. 11. Penis, caudal view. 12. Coxae 2, anterior view. 13. Flagellum. 14. Leg pair 1, anterior view. 15. Vulva, posterior view. 16. Right promere, posterior view. 17. Distal part of flagellum. 18. Distal part of right promere, posterior view. Scales: 10 μm (Figs 17, 18), 20 μm (Figs 10, 11, 12, 14), 100 μm (Figs 13, 15, 16).

FIGURES 19–20. Nepalmatoiulus jianchuanensis sp. nov., male holotype (ZMUM). 19. Opisthomere, mesal view. 20. Opisthomere, mesal view (slightly turned back). Scale: 100 μm.