Nepalmatoiulus sichuanensis, Mikhaljova, 2020

Mikhaljova, Elena V., 2020, New data on the fauna of China, part I: the taxonomy of the millipede family Julidae (Diplopoda), Zootaxa 4729 (1), pp. 47-66 : 48-50

Nepalmatoiulus sichuanensis new species

Figs 1–12

Material examined: Holotype: male ( ZMUM), China, Sichuan Province, SW Mianning, 3360 m asl., 28°13´11´´ N, 101°44´13´´ E, 6 July 2011, leg. I. Belousov and I. Kabak.

Diagnosis. The species seems to be particularly closely related to Nepalmatoiulus polyakis Enghoff, 1987 from China, Sichuan Province, Suining, but differs in the slender subulate gonopod solenomere, the absence of pointed processes on the posterior solenomeral flap, a velum with finely serrated margin, a hook-shaped apically papillate mesomeral process ( Figs 5 , 9 ) as well as the presence not less than 10 nonapical stipital setae of gnathochilarium.

Description. Male. Length about 20 mm, vertical diameter 2.0 mm, with 47(– 2) rings, excluding telson. Coloration grey-brown on dorsum and the sides just below ozopore level; prozona marbled dark brown; venter and bottoms of the sides white. Head dark brown with marble occiput and clypeolabral part. Collum with two transversely-oval, large, marble spots. Antennae dark brown, eyes black. Legs and telson brown. Head smooth, with 2 epicranial setae, 4 supralabral setae, and 16 labral setae. Eye patches subtriangular, each composed of 32–34 ocelli. Antennae relatively long, rather slender and clavate. Length ratios of antennomeres 2–7 as 6.1:5.8:5.7:5.8:3.1:1, width ratios as 1.0:1.0:1.0:1.4:1.3:1, respectively. Gnathochilarium: not less than 10 nonapical stipital setae; lamel- lae linguales each with 4 setae (in examined male) arranged longitudinally. Mandibular stipites with well-developed rounded lobes covered with vertical (extending from lobe base to apex) striae. Collum laterally with numerous distinct lower striae extending from posterior to anterior margin, dorsally with indistinct short striae at posterior margin only. A transverse row of sparse, thin relatively long setae at hind edge of collum. Body rings circular. Prozona smooth. Suture between pro- and metazonite distinct. Metazona with dense, regular, longitudinal striae reaching hind margin (12–13 striae in an approximate square with sides equal to metazonital length of a midbody ring). 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 dividing pro- and metazona, touching the suture only in the anterior portion of the body, slightly set off from the suture in the posterior half of the body. Limbus with rectangular lobes, corners rounded (Type 5 or 6 in Enghoff 1987). Telson with caudal dorsal projection straight and very 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. Pregonopodal legs stronger and thicker as compared to other legs, devoid of ventral pads. Postgonopodal legs with ventral, delicately serrate pads on postfemur and tibia; pads somewhat decreasing in size towards telson. Claw of all legs at base with a long (much longer than claw) setiform accessory claw ventrally but without accessory claw dorsally ( Fig. 1 ). Leg pair 1 forming a smooth hook; the distal ring not coming into close contact with the basal rings (“open hook” type in Enghoff 1987), postfemur with inflated scaly-rugose ventral surface, tip with rugosity, coxa with several setae, distal ring without setae ( Figs 11, 12 ). Coxa 2 with numerous mesapical setae and gland openings positioned in basal and lateral position ( Fig. 2 ). Penis about 2.5 longer than wide ( Fig. 8 ). Ventral margin of body ring VII with ventrad subtriangular apically rounded lobes. Gonopods slightly protruding. Anterior gonopod (promere) flattened, with subparallel margins, apically obliquely rounded, subapically excavated for accommodation of mesomeral process; scarcely rugose margin of apical excavation produced into short blunt caudad protrusion (pa); posterior surface subcentrally with knoblike flattened rudimentary telopodite ( Figs 3–4 , 10 ). Flagellum slender, long, covered with cuticular spikes ( Fig. 6 ). Opisthomere with hook-shaped mesomeral process frontally rugose ( Figs 5, 7 , 9 ). Margin of velum with fine folds but anteriorly smooth and posteriorly with tiny denticles. Solenomere short, smooth, pointed.

Female unknown.

Etymology. The specific epithet refers to the type locality.

Figures

FIGURES 1–8. Nepalmatoiulus sichuanensis sp. nov., male holotype. 1, claw of leg 2; 2, leg pair 2, front view; 3, promere, caudal view; 4, apex of promere, caudal view; 5, opisthomere, mesal view; 6, portion of promere flagellum; 7, apex of opisthomere mesomeral process; 8, penis, front view; pa, protrusion of promere apex. Scales: 10 μm (Figs 1, 4, 6, 7), 20 μm (Figs 3, 5, 8), 100 μm (Fig. 2).

FIGURES 9–12. Nepalmatoiulus sichuanensis sp. nov., male holotype. 9, opisthomere, mesal view; 10, promere, caudal view; 11, leg 1, front view; 12, leg 1, lateral view; pa, protrusion of promere apex. Scales in mm.