Nepalmatoiulus hexiensis, 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 : 117-119

Nepalmatoiulus hexiensis , new species

Figs 62–70

Material examined. Holotype: male ( ZMUM), China, Yunnan Province, N Lanping, 11.3 km SW of Hexi , 26°48´34´´ N, 99°17´16´´ E, H = 3600 m, 10 June 2016, leg. I. Kabak, G. Davidian.

Diagnosis. Differs from congeners mainly by the gonopod mesomeral process with apical excavation and subapical digitiform outgrowth, the absence of velar process and a very short, laterally compressed solenomere coupled with a relatively small body length.

Description. Male. Length about 20 mm, midbody vertical diameter about 2.5 mm, with 50 (–3) segments, excluding telson. Coloration (in alcohol) dark brown with two broad longitudinal light brown dorsal stripes. Venter, including basal parts of legs, lighter. Antennae dark brown, eyes black. Collum with two large transversely-oval, marbled brown spots. Head marbled-brown excluding light brown ventral part and dark brown stripe between eyes. Head smooth with several setae between and below antennae. 2 epicranial setae, 4 supralabral setae, not less than 14 labral setae. Eye patches almost oval, composed of about 40 ocelli. Antennae medium-sized, rather slender and clavate. Gnathochilarium with not less than 7 nonapical stipital setae. Mandibular stipite with smooth subtriangular oval lobe. Not less than 5 setae on each lamella linguales. Collum laterally with several distinct longer lower striae at posterior margin, not reaching to anterior margin, dorsally with short indistinct striae at posterior margin only. Length of the collum striae gradually decreasing toward dorsum. A transverse row of sparse setae at hind edge of collum. Body segments circular. Prozona smooth except for ventral part with very shallow obliquely located striae. Metazona with dense, regular, longitudinal striae reaching hind margin (11–12 striae in an approximate square with sides equal to metazonital length of a dorsal side of midbody ring). Limbus straight, smooth (of Type 1 in Enghoff 1987). A transverse row of thin setae at hind edge of metazonites, setae gradually growing longer and denser toward telson. The metazonite gradually growing somewhat narrower toward body venter. Ozopores small, lying immediately behind suture dividing pro- and metazona. Caudal dorsal projection of telson long, covered with dense setae and tipped with a small claw-shaped process directed caudad. Preanal ring, anal valves, and subanal scale very 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 relatively long (longer than claw) setiform accessory claw ventrally but without accessory claw dorsally. Leg pair 1 forming a hook, the distal segment not touching basal segments (“Open hook” type in Enghoff 1987); postfemur with slightly scaly-rugose ventral surface, tip indistinctly wrinkled; coxa with one seta, distal segment without seta and tarsal remnant ( Fig. 62 ). Coxa 2 with one mesapical oral seta, apparently with a gland opening positioned in central and axial position according to Enghoff 1987 ( Fig. 63 ). Penis short, with approximately equal length and width ( Fig. 67 ). Ventral margin of body segment VII with lobes similar to figure 32 in Enghoff 1987. Anterior gonopod flattened, with subparallel margins, apically obliquely rounded. Anterior gonopod in posterior view subapically excavated for accommodation of mesomeral process, mesal margin strongly bent caudad, distal margins of the excavation papillate, rugose margin of apical excavation produced into small caudad protrusion ( Figs 64, 66 ). This gonopod subcentrally with knob-like flattened rudimentary telopodite. Flagellum slender, relatively short, covered with cuticular spikes in the distal part; the basal part of the flagellum is probably without protrusions ( Figs 64, 65 ). Opisthomere mesomeral process anteriorly excavated, mesally with digitiform outgrowth ( Figs 68, 69 ). Solenomere very short, laterally compressed, striate, apically spinose ( Fig. 70 ). Membranous velum with strongly sloped smooth margin, without a notch near the mesomeral process. Margin of accessory membrane slightly undulated. A flap arising from posterior margin of solenomeral furrow with well-developed pointed process.

Female unknown.

Etymology. The specific epithet refers to the type locality.

Figures

FIGURES 62–67. Nepalmatoiulus hexiensis sp. nov., male holotype. 62, leg pair 1; 63, coxae 2, front view; 64, promere, caudal view; 65, distal part of flagellum; 66, distal part of promere; 67, penis. Scales: 20 μm (Figs 62–63, 65– 67), 100 μm (Fig. 64).

FIGURES 68–70. Nepalmatoiulus hexiensis sp. nov., male holotype. 68, opisthomere, mesal view; 69, distal part of mesomeral process; 70, solenomere. Scales: 10 μm (Figs 69–70), 100 μm (Fig. 68).