Polydrepanum fissum, Sankaran & Sebastian, 2018

Sankaran, Pradeep M. & Sebastian, Pothalil A., 2018, A new species of and a new transfer from the millipede genus Polydrepanum Carl, 1932 (Polydesmida, Paradoxosomatidae, Polydrepanini), Zootaxa 4471 (1), pp. 169-178 : 170

Key to Polydrepanum species, based on male features

[Since Bano and Murthy (1997) did not formally describe their Polydrepanum spp., these species are omitted from the key. Details of all Polydrepanum spp. except P. fissum sp. nov. are adopted from Carl (1932) and Golovatch (1984)].

1a Only leg pair II possesses adenostyle, gonopodal femorite well torsate............................................ 2

1b Leg pairs I & II possess adenostyle ( Fig. 3A–B ), torsion of gonopodal femorite incomplete ( Figs 3E–F , 4A–B )......................................................................................... Polydrepanum fissum sp. nov.

2a Gonopodal femorite stout, tibiotarsus lacks lateral process, solenophore and solenomere strongly coiled distally ( Fig. 6C )..................................................................................... .. Polydrepanum tamilum

2b Gonopodal femorite slender, tibiotarsus with lateral process/processes, solenophore and solenomere without distal coiling ( Fig. 6A–B ).............................................................................................. 3

3a Tibiotarsus with single lateral process and without mesal process, lamina lateralis with finger-shaped extension ( Fig. 6B )..................................................................................... Polydrepanum horridum

3b Tibiotarsus with paired lateral processes and rod-shaped mesal process, lamina lateralis lacks extension ( Fig. 6A )......................................................................................... Polydrepanum asperrimum

Figures

FIGURE 3. Polydrepanum fissum sp. nov., male legs (A–D) and gonopod (E–F). A: Leg pair I, ventral view (insets adenostyle on right femur 1, lateral view (left) and tarsus of the right leg showing tarsal brush, lateral view (right)). B: Left leg of haplosegment 2, mesal view (inset tarsus of the same showing tarsal brush, mesal view). C: Left leg of haplosegment 3, mesal view (inset tarsus of the same showing tarsal brush, mesal view). D: Tarsus of right anterior leg of diplosegment 4 showing tarsal brush, mesal view. E: Right gonopod, ventral view. F: Same, mesal view. Scale bars: A–C, E–F 0.5 mm; D 0.2 mm.

FIGURE 4. Polydrepanum fissum sp. nov.. A: Right gonopod, ventral view. B: Same, mesal view. C: Same, lateral view. Abbreviations: C = cannula, dlLF = distolateral lobe of femorite, dlLL = distolateral lobe of lamina lateralis, F = femorite, FF = fold of femorite, GC = gonocoxa, LL = lamina lateralis, LLp = lateral lamellate process of solenophore, mLL = mesal extension of lamina lateralis, mTp = mesal triangular process of solenophore, MWp 1 & 2 = membranous wing-like process of solenophore 1 and 2, PF = prefemur, SG = seminal groove, Sm = Solenomere, Sp = Solenophore. Arrows indicate tip of solenomere (3), branches of solenophore tip (1–2) and distoventral, long, stiff seta of prefemur (4). Scale bars: A–B 0.5 mm; C 0.2 mm.

FIGURE 6. Previously known Polydrepanum spp.. A: Polydrepanum asperrimum (Carl, 1932) (reproduced from Carl (1932)). B: Polydrepanum horridum Golovatch, 1984 (reproduced from Golovatch (1984)). C: Polydrepanum tamilum Carl, 1932 (reproduced from Carl (1932)). D–F: Undescribed Polydrepanum spp.: D: Polydrepanum sp. 1; E: Polydrepanum sp. 2; F: Polydrepanum sp. 3 (all reproduced from Bano & Murthy (1997)). All figures not to scale.