Ommatoiulus ktarii sp. nov.

Diagnosis. A species of the genus Ommatoiulus, most similar to O. rimosus (Karsch, 1881) (see Akkari (2013) for a redescription) in the general shape of promerite with a protruding mesal ridge and a subapical plate bearing large setae, elongated and curved mesomerite, long distal process and serrated lamella of solenomerite, and a stout and apically folded paracoxite. Distinct from it in the promerite differing in the longer mesal distal process and a uniformly rounded lateral process (vs. angular in O. rimosus); a broader subapical fold, not higher than half the distal process (vs. almost as high as the mesal distal process in O. rimosus); posterior gonopods differing in the distal part of the mesomerite which is curved, pointing meso-posteriad (vs. strongly curved, making almost a full loop, pointing meso-anteriad in O. rimosus), in a stouter and longer paracoxite of the same length as solenomerite (vs. paracoxite shorter than solenomerite in O. rimosus) and in details of the distal part of the solenomerite with a shorter distal process (ds) and a less broad distal lamella (dl) in the new species.

Name. The species epithet honours the Tunisian Zoologist and Emeritus Professor Mohamed Hédi Ktari, who inspired the first author to engage in the study of myriapods and for his tremendous support to her scientific work in her debuts in Tunisia.

Material examined. Holotype: male, TUNISIA, Kairouan Governorate, Oueslatia, N 35.8139, E 9.6550, 17.10.2017, mixed forest of Pinus halepensis, in litter and under stones, Hans Reip leg. (NHMW MY 10328) . Paratypes: 1 male, 1 female, 2 juveniles (NHMW MY 10329); 1 male (SMNG VNR 020846), same data as holotype .

Description. Measurements. Males: body length: 16–18 mm, vertical diameter: 1.4–1.6 mm, 43–46 podous rings + 0–2 apodous rings + telson, antennae length: 1.03–1.06 mm, antennae/vertical diameter ratio: 0.67–0.74, midbody leg length: 0.68–0.79 mm, ratio midbody leg/vertical diameter: 0.48–0.50. Female: body length: 21.5 mm, vertical diameter: 2.1 mm, 45 podous rings + 1 apodous ring + telson, antennae length: 1.08 mm, antennae/vertical diameter ratio: 0.51, midbody leg length: 0.84 mm, ratio midbody leg/vertical diameter: 0.4.

Colour (Fig. 1). General colour dark brown fading into pale-yellowish below ozopore level. Head (Fig. 1A–C) dark brown with lighter brown to yellowish sputter, paler towards the labral zone; antennae, stipes of the mandibles and gnathochilarium brown, labrum yellowish. Collum and anteriormost rings uniformly dark brown with light brown-yellow sputter (Fig. 1B). Posterior to that, colour contrasting with dorsally uniformly dark almost black prozonites fading on the lateral sides, and pale whitish metazonites (Fig. 1A, B, E). Legs pale whitish (Fig. 1D), gonopods more pigmented (Fig. 1A, B). Anal valves and preanal ring brown; preanal ring projection and subanal scale pale yellowish to white (Fig. 1E).

Head (Fig. 1A–C). With 8–10 vertical rows of ommatidia. Labrum tridentate. Gnathochilarium typical for Julidae .

Body rings (Fig. 1A, B, E). Metazonites with regular longitudinal striae, denser on the lateral sides; prozonites with denser and irregular oblique striae. Ozopores as small and round transparent openings at half their diameter distance from the posterior margin of the metazonites. Suture complete, rectilinear, slightly curving at the level of ozopores in the posteriormost body rings. Preanal ring (Fig. 1E) protruding into a straight caudal projection, bearing a few short setae on tip and an upturned hyaline process. Anal valves with a marginal row of long setae and a submarginal row of ca. 4–5 shorter setae. Subanal scale semi-circular, with several setae.

Male sexual characters. Mandibular stipites ventrally enlarged into rounded lobes (Fig. 1A, B), first pair of legs hook-shaped, the rest of the leg-pairs with postfemoral and tarsal pads (Fig. 1D). Gonopods (Figs 2, 3). Promerite (Figs 2A, C, D, 3A–D) with a broad rounded lateral margin, distally with an incision (i) and an asymmetrically square-like subapical lobe with a thickened margin (Fig. 2A, C, D); mesal ridge (M) apically protruding beyond the subapical lobe as a narrow cylindrical process with a blunt tip. In posterior view (Fig. 2D), the distal margin shows an oblique ridge connected with the mesal apical process, bearing circa six-seven strong setae pointing distolaterad and subapically circa three-four shorter ones close to the mesal ridge. Mesomerite (Ms) (Figs 2B, E, F, 3E–H) large and higher than the other processes, proximal part uniformly broad, abruptly narrowing at the upper third and distally curving meso-posteriad in a hook-shaped process (ho) (Fig, 2E); distal part gently narrowing into a thin apex, lateral margin of mesomerite marking an angle at the site of the curvature (Figs 2F, 3E, H). Solenomerite (S) broad at the basis, with a row of scattered spikes (Sp), and a deep notch (n) separating the main process from a small triangular scaly process (pr), distally with a hyaline lamella (dl) and a long process (ds) (Figs 2B, 3E–G), long, gradually narrowing and curving latero-distad, showing a small straight conical ramification at the level of the curvature; distal lamella (dl) with two main folds bearing several serrations and an acuminate tip (Figs 2B, 3F, G). Seminal groove (g) originating from the fovea (F) visible in mesal view (Figs 2E, 3E), running postero-distad towards ds. Paracoxite (Px) simple, uniformly broad, of the same length as solenomerite, distally bent posterio-mediad, and apically folded (Figs 2B, E, F, 3E–H). Coxite (Co) showing as a round broad projection (Figs 2B, 3F, G).

Distribution. Known only from the type locality in Tunisia.

Habitat. Found under stones and in litter of a Pinus halepensis forest mixed with Juniperus sp. and diverse deciduous shrubs.