Namibostreptus kymatorhabdus ( Attems 1914 )

Mwabvu, Tarombera, Hamer, Michelle, Slotow, Robert & Barraclough, David, 2009, A revision of the taxonomy and distribution of Spirostreptus Brandt 1833 (Diplopoda, Spirostreptida, Spirostreptidae) with descriptions of a new species and a new genus of spirostreptid millipede, Zootaxa 2211, pp. 36-56 : 50-52

Namibostreptus kymatorhabdus ( Attems 1914)

Fig. 8

Spirostreptus kymatorhabdus Attems 1914 , p. 151, figs 147–149; Hoffman 2008

Triaenostreptus kymatorhabdus: Attems 1928 ; Hoffman 1971; Krabbe 1982; Hamer 1998

Type material: Holotype: NAMIBIA: 1 3, Walfishbay [22 0 38'S, 14 0 39'E], Colonoal-Gesellschaft ( ZMB 2043).

Additional material examined: NAMIBIA: 1 3, Lubbert ( ZMB 5197); 1 3, Daan Viljoen Game Park 30 km north of Windhoek [22 0 32'S, 17 0 41'E], 24.ii. 1978, O. Lomholdt & E. Wederkinch ( ZMUC uncatalogued). Diagnosis: See generic diagnosis.

Description: Size: Body length 210 mm; minimum and maximum body width 9–11 mm and 11–12 mm; antenna length 8–12 mm.

Number of body rings: 62–74.

Colour: Body black or dark brown; legs and antennae brown.

Head: Regularly spaced striations present behind and between the lateral edges of eyes; gnathochilarium with a triangular median prebasilar sclerite.

Collum: Anteriorly produced into a short rounded lateral lobe, with 3–4 complete and 2 or more incomplete folds.

First ozopore: On 6th body ring.

Pre-femoral process: Proximally rounded with a short laterally deflected medial nipple ( Fig. 8 c).

Gonopod s: ( Figs 8 a, 8b) 8–9 mm long. Gonopod surface smooth, without ridges or humps; distal telocoxite with an end process. Orally medial edges of telocoxite parallel, raised and folded laterally, fold becomes broader distally, ending in a flat end process.

Sternite triangular, reaching the level of the paracoxite apex; paracoxite apically horizontal and tightly fused to the metaplica.

Proplica about half the length of gonopod; apical proplica broad with a concavity and acute medial tip.

Lateral and medial edges of proplica pronounced subapically, with shallow central groove, lateral edge more pronounced than medial edge. Orally distal depression separates proplica from the larger convex lateral lobe of the distal telocoxite.

Metaplica with a broad, convex-shaped lateral lobe (wider than it is long and distal to proplica apex) which extends beyond lateral edge of proplica; a smaller distal lateral process parallel to paracoxite apex present proximal to end process. Metaplica with a window through which part of telopodite is visible. Wide depression present adjacent to the convex lobe, distal to the point of emergence of telopodite.

Telopodite long, with a trifurcate ending. Antetorsal process crescent-shaped and tapering ( Figs 8 a, 8b), extending past paracoxite apex. Distally, antetorsal process with a terminal spine, bending medially past lateral edge of proplica; post knee telopodite lamellate with a loose coil preceding abrupt narrowing.

Distribution: Known only from the west coast of Namibia and near Windhoek ( Namibia).

Remarks: The lack of a lateral lobe and the lack of a laterally rounded distal lobe, the shorter proplica, and the abrupt narrowing of the telopodite (distal to the telopodite coil) are character states that do not support placement in Spirostreptus . Based on Hoffman’s (2008) diagnosis of the Spirostreptini, kymatorhabdus is a member of the tribe, the telopodite structure and the prostatic groove resemble member genera. However, the shape and size of the distal coxite of the gonopod of kymatorhabdus differ from other Spirostreptini genera by having a unique convex lobe. Therefore, we erect Namibostreptus to accommodate kymatorhabdus , this bringing the number of genera in Spirostreptini to six.

Figures

FIGURE 8. Namibostreptus kymatorhabdus (ZMB 2043). a, oral view of gonopods; b, aboral view of gonopods; c, oral view of prefemoral lobe of first pair of male legs; d, lateral view of collum. Abbreviations: p, proplica; m, metaplica; clb, convex lateral lobe; dlp, distal lateral process; ep, end process; tp, telopodite; at, antetorsal process; pc, paracoxite; cf, collum fold; al, anterior lobe; pfl, prefemoral lobe.