Nepalmatoiulus uncinatus, Mikhaljova, 2020

Mikhaljova, Elena V., 2020, New data on the fauna of China, part II: the millipede genus Nepalmatoiulus Mauriès, 1983 (Diplopoda, Julidae) in continental China and Taiwan, with descriptions of seven new species, Zootaxa 4852 (1), pp. 101-124 : 105-107

Nepalmatoiulus uncinatus , new species

Figs 12–26

Material examined. Holotype: male ( ZMUM), China, NW Yunnan Province, NW Deqen, NW Adenggong, 28°36´36´´ N, 98°50´14´´ E, H = 4220 m, 12 June 2014, leg. I. Belousov, I. Kabak ; Paratypes: 2 females ( ZMUM), same locality as in holotype, 12 June 2014, leg. I. Belousov, I. Kabak.

Diagnosis. Differs from congeners mainly by the presence of subcentral digitiform outgrowth of the posterior gonopod mesomeral process and irregular subapical protrusions located on mesal side of the mesomeral process as well as absence of velar process (see Discussion below).

Description. Male. Length about 37 mm, midbody vertical diameter 3.2 mm, with 53 (–1) segments, excluding telson. Coloration (in alcohol) dark brown. Anterior and ventral portions of head yellow. Eyes black. Legs brown. Head smooth. 2 epicranial setae, 4 supralabral setae, and 22 labral setae. Eye patches almost rectangular, composed of 50–53 ocelli. Antennae medium-sized, rather slender and clavate. Length ratios of antennomeres 2–7 as 2.5:1.9:1.9:1.9:1.5:1, width ratios as 1.4:1.5:1.6:1.9:1.4:1. Antennomeres 5 and 6 with incomplete distodorsal corolla of sensory bacilli ( Fig. 16 ). Mandibular stipites with subrectangular rounded smooth lobes. Gnathochilarium: not less than 20 nonapical stipital setae; lamellae linguales each with at least 7 setae arranged longitudinally ( Figs 12, 17 ). Collum laterally with distinct lower striae of different length at posterior margin not reaching to anterior margin, dorsally with indistinct short striae at posterior margin. A transverse row of setae at hind edge of collum. Body segments circular. Prozona smooth except for ventral part with shallow obliquely located striae, and for dorsal part with transverse very indistinct striae. Metazona with dense, regular, longitudinal striae reaching hind margin (18–20 striae in an approximate square with sides equal to metazonital length of a dorsal side of a midbody ring). The metazonite gradually growing narrower toward ventral body part. 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 immediately behind suture dividing pro- and metazona. Caudal dorsal projection of telson 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 long (longer than claw) setiform accessory claw ventrally but without accessory claw dorsally. Leg pair 1 forming hook, the distal segment not touching basal segments (“Open hook” type in Enghoff 1987); femur and postfemur with scaly-rugose ventral surface, tip delicately wrinkly; coxa with one seta, distal segment without seta and tarsal remnant ( Fig. 18 ). Coxa 2 with one mesapical oral seta, a gland opening positioned in apical and axial position according to Enghoff 1987 ( Figs 13–14 ). Penis subrectangular, about 1.8 longer than wide, with apical protrusion ( Fig. 15 ). Ventral margin of body segment VII with lobes similar to figure 32 in Enghoff 1987. Gonopods slightly protruding. Anterior gonopod flattened, with parallel margins, apically rounded, in posterior view subapically excavated for accommodation of mesomeral process; distally (excluding an excavation) papillate; subcentrally with knoblike flattened rudimentary telopodite ( Figs 19, 22 ). Flagellum enough long, slender, caudally covered with cuticular conical denticles in the distal part ( Fig. 26 ); (failed to see the basal part of the flagellum). Opisthomere with: distally hook-shaped mesomeral process, subcentral digitiform outgrowth (d), and irregular subapical protrusions (p) located on mesal side of the mesomeral process ( Figs 20–21 ). Membranous velum with strongly sloped smooth margin, without a notch near the mesomeral process. Long and slender solenomere spinose throughout (posteriorly with particularly long spines) ( Figs 20, 24 , distal part of the solenomere broken). Accessory membrane well-developed with smooth margin. Acicular process of a flagellum-quiding flap arising from posterior margin of solenomeral furrow well-developed.

Female. Length 37–38 mm, midbody vertical diameter 3.9–4.0 mm. Gnathochilarium without nonapical stipital setae. Vulva with operculum and bursa of about equal height; apical lobes of bursa not long ( Figs 23, 25 ).

Etymology. The specific epithet refers to the subcentral outgrowth of the posterior gonopod mesomeral process.

Figures

FIGURES 12–18. Nepalmatoiulus uncinatus sp. nov., male holotype. 12, gnathochilarium; 13, leg pair 2, front view; 14, coxae 2, front view; 15, penis; 16, distal part of antenna; 17, nonapical stipital setae of gnathochilarium; 18, leg 1. Scales: 20 μm (Figs15–18), 100 μm (Figs 12–14).

FIGURES 19–26. Nepalmatoiulus uncinatus sp. nov., male holotype and female paratype. 19, promere, caudal view; 20, gonopods, mesal view; 21, distal part of mesomeral process; 22, distal part of promere; 23, vulva, front view; 24, solenomere and accessory membrane (distal part of the solenomere broken); 25, vulva, caudal view; 26, distal part of flagellum; d, outgrowth of opisthomere mesomeral process; p, protrusions. Scales: 10 μm (Figs 21–22), 20 μm (Figs 24, 26), 100 μm (Figs 19–20, 23, 25).