Nepalmatoiulus tuoxiaensis, Mikhaljova, 2023

Mikhaljova, Elena V., 2023, Descriptions of the new species of the genus Nepalmatoiulus Mauriès, 1983 from China, with notes on the closely coexisting species (Diplopoda, Julida, Julidae), Zootaxa 5297 (3), pp. 380-392 : 388-390

Nepalmatoiulus tuoxiaensis sp. nov.

Figs 27–38

Material examined. Holotype: male ( ZMUM), China, Yunnan Province, Deqin, Tuoxia Highway Mt. Range btw Xiaruolisuzuxiang & Yezhizhen, 27°40´2´´ N, 99°10´29´´ E, H = 4080 m, crooked Rhododendron forest, under rotten wood, or sifter, 13.06. 2013, leg. I. Belousov, I. Kabak, G. Davidian.

Diagnosis. Differs from congeners mainly by the opisthomere mesomeral process with slender subcylindrical apex and subapical excavation (ex in Fig. 38 ), by the velum with long, deep, sloped, arcuate smooth margin, by not expanded, rounded promere apex with papillae only on mesal margin of the posterior excavation and without protrusion of the margin and by the brownish-dark grey body coloration. Particularly similar to Nepalmatoiulus deqenensis Mikhaljova and Nepalmatoiulus acutidentatus Mikhaljova , but differs from these species by certain characters (see Discussion below).

Description. Male. Length in alcohol about 25.0 mm, midbody vertical diameter about 2.0 mm, with 47(–1) rings, excluding telson. Coloration in alcohol brownish-dark grey. Venter (including basal parts of legs) brown. Legs dorsally and antennae dark brown. Occiput, forehead and collum from black brown to dark brown, ventral parts of head and labrum light brown. Eyes black.

Head smooth, 2 epicranial setae, 4 supralabral setae; not less than 14 labral setae. Eye patches almost oval, composed of about 50 ommatidia. Antennae medium-sized, rather slender and clavate. Gnathochilarium with no less than 16 nonapical stipital setae; lamellae linguales each with not less than 5 setae; mandibular stipites each with subtriangular rounded smooth lobe; apical portion of the lobe without well demarcated border.

Collum laterally with several distinct longer lower striae at posterior margin, not reaching to anterior margin, dorsally with short striae at posterior margin only. Length of collum striae gradually decreasing toward dorsum. A transverse row of sparse setae at hind edge of collum. Body rings circular. Prozona smooth. Metazona with dense, regular, longitudinal striae reaching hind margin (17 or 18 striae in an approximate square with sides equal to metazonital length of a dorsal side of midbody ring). The metazonite gradually growing somewhat narrower toward body venter. Limbus straight, smooth (of Type 1 in Enghoff 1987). A transverse row of thin sparse setae at hind edge of metazonites, setae gradually growing longer and denser 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 sparsely setose; anal valves densely setose distally; subanal scale densely setose only in posterior half.

Legs relatively short and slender. Very delicately serrate ventral pads on postfemur and tibia, starting from legs 2 ( Fig. 29 ). Ventral pads gradually decrease towards telson; tibia of most hind legs with ventral pads on distal part only. Claw of all legs at base with a setiform accessory claw ventrally ( Fig. 32 ). Leg pair 1 forming hook, distal segment not in close contact with basal segments (“Open hook” type in Enghoff 1987). Leg pair 1: postfemur with slightly scaly-rugose ventral surface; coxa with one seta; distal segment without tarsal remnant ( Fig. 27 ); tip ventrally without rugosity ( Fig. 28 ). Coxa 2 with one mesapical oral seta, a gland opening positioned in apical and axial position ( Figs 29–30 ) according to Enghoff 1987. Penis subtrapezoidal, about 1.4 longer than wide ( Fig. 31 ). Ventral margin of body ring VII with lobes similar to figure 32 in Enghoff 1987.

Gonopods slightly protruding. Anterior gonopod flattened, with subparallel margins, apically relatively obliquely rounded, in posterior view subapically excavated for accommodation of mesomeral process, only mesal margin of the excavation papillate, subcentrally with knoblike flattened rudimentary telopodite ( Figs 33, 35 ). Flagellum slender, short, covered with cuticular spikes in distal part ( Fig. 34 ). Opisthomere mesomeral process with slender subcylindrical apex and subapical excavation (ex) ( Figs 36, 38 ). Membranous velum with long, deep, sloped, arcuate smooth margin and without a notch near the mesomeral process. Margin of accessory membrane poorly serrate. Solenomere relatively short, spinose throughout ( Fig. 37 ).

Female unknown.

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

Figures

FIGURES 27–32. Nepalmatoiulus tuoxiaensis, sp. nov., male holotype (ZMUM). 27. Leg pair 1, anterior view. 28. Apex of leg 1, anterior view. 29. Leg pair 2, anterior view. 30. Coxae 2, anterior view. 31. Penis, caudal view. 32. Claw 2, anterior view. Scales: 10 μm (Figs 28, 32), 20 μm (Figs 30–31), 100 μm (Figs 27, 29).

FIGURES 33–38. Nepalmatoiulus tuoxiaensis, sp. nov., male holotype (ZMUM). 33. Left promere, caudal view. 34. Distal part of flagellum. 35. Distal part of left promere, caudal view. 36. Opisthomere, mesal view. 37. Solenomere, mesal view. 38. Anterior part of opisthomere, mesal view. Abbreviation: ex, excavation. Scales: 10 μm (Figs 34–35, 37), 20 μm (Fig. 38), 100 μm (Figs 33, 36).