Pelmatoiulus tectus ( Cook, 1897 ) Fiemapong & Enghoff, 2018

Fiemapong, Armand Richard Nzoko & Enghoff, Henrik, 2018, A giant African millipede re-discovered, re-located and re-classified after 120 years (Diplopoda, Spirobolida, Pachybolidae), Zootaxa 4527 (3), pp. 403-413 : 404-407

Pelmatoiulus tectus ( Cook, 1897) , new combination

Figs 1–7

Pachybolus tectus Cook, 1897 . Type-locality: Zanzibar. Holotype (only specimen known until now) said by Cook (1899) to be in the museum at Hamburg, but missing from that collection ( Weidner 1960).

Material studied. 1♂ Cameroon, littoral evergreen forest, Sanaga Maritime Division , Yansoki, 04°20’N, 009°83’E, secondary forest, 17.x.2017, A.R. Nzoko Fiemapong & A. Yetchom Fondjo leg. ( ZMUC) ; 1♀ Cameroon, littoral evergreen forest, NKAM Division , Djawara, 04°21’N, 009°76’E, 10.ix.2017, A.R. Nzoko Fiemapong leg. ( ZMUC) ; 1♂ Cameroon, Littoral Evergreen Forest Region , Yabassi, 4°95′N, 010°24′E, secondary forest, under dead leaves, 27.I.2017, A.R. Nzoko Fiemapong leg. ( ARNF) .

Descriptive notes. The following notes are based on the newly studied material.

Male. Body length ca. 15 cm, diameter 1.5 cm, 53 podous body rings + telson (no apodous body rings in front of telson).

Colour of live animals ( Fig. 1 ). Head, collum and telson brown; body ringed in black, orange and yellow, each body ring divided into a bright yellow anterior zone, an orange-red intermediate zone and a strongly contrasting, deep black posterior zone; antennae, legs and venter yellow-brown.

After one year in alcohol head, antennae, collum, legs and telson reddish brown; body rings with pro- and mesozona rust red, metazona black.

Incisura lateralis closed. Antennae with ca. 30 apical sensilla ( Fig. 2 A–D); tip of sensilla with a pore surrounded by finger-shaped processes ( Fig. 2 C ). Antennomeres 5 and 6 with dorso-apical fields of small sensilla ( Fig. 2 D ). Gnathochilarium: stipites (st) each with 4–6 apical setae; lamellae linguales (ll) each with two setae arranged in a transverse subapical row ( Fig. 2 E, F ). Legs from third to last pair with large tibial pads.

Anterior gonopods ( Figs 3 A–B, 4 A–B) exactly as illustrated by Cook (1899): sternum (st) with a large, tongue-shaped, broadly rounded median lobe; coxae (cx) ca. 25% longer than sternal lobe, apically broadly rounded; telopodites (tlp) longer than sternal lobe, but shorter than coxae, in posterior view strongly narrowed at ca. 2/3 of their length, apical part a rounded lobe (lo, tip of lo visible in anterior view), mesal margin of telopodite broadly bent posteriad, forming a sigmoid flange (s f) ending in apical lobe.

Posterior gonopods ( Figs 3 C–D, 4 C, 5 A–B) also exactly as illustrated by Cook (1899): a single, slender, Cshaped sclerite with an irregularly rounded process (pr) at base, close to articulation with tracheal apodeme; at ca. 2/3 from base with constriction (cn), tip folded mesad, forming a broadly rounded apical lobe (al). A poorly sclerotized, obliquely striate area (sa) covering middle 1/3 and ending at constriction on external side of the "C". Efferent groove (eg) (cf. Enghoff 2011) running along inner curvature of "C", ending near gonopod apex at bentover side of apical lobe.

Female. Body length ca. 15 cm, diameter 1.5 cm, 54 podous body rings + telson (no apodous body rings in front of telson).

Non-sexual characters as in male, except antennae with 20–25 apical sensilla and gnathochilarial stipites each with 3 or 4 apical setae.

Vulvae ( Fig. 6 ) kidney-shaped; valves in basal half meeting in almost straight line, mesal margins with numerous short setae from level of tip of small operculum (op) almost up to highest point of valves ( Fig. 6 B, D ), in apical half with poorly sclerotized margins, margin of lateral valve with large rounded lobe (lb).

Figures

FIGURE 1. Pelmatojulus tectus (Cook, 1897), live specimen from Cameroon.

FIGURE 2. Pelmatojulus tectus (Cook, 1897), male from Cameroon, A–D. Right antenna. A. Apical view. B. Close-up of a dyad of sensilla from apical (7th) antennomere. C. Tip of sensillum from apical antennomere. D. Apico-dorsal sensilla from 6th antennomere. E–F. Gnathochilarium. Abbreviations: ll = lamella lingualis, st = stipes. Scale bars = 0.5 mm (E–F), 0.1 mm (A), 0.01 mm (B, D), 0.001 mm (C).

FIGURE 3. Gonopods of Pelmatojulus tectus (Cook, 1897) (A–D) and P. togoensis (Cook, 1897) (E–G), after Cook (1899), rearranged. A, E. Anterior gonopods, anterior view. B: Anterior gonopods, posterior view. C, F. right posterior gonopod, anterior view. D, G. right posterior gonopod, posterior view. Not drawn to scale.

FIGURE 4. Gonopods of Pelmatoiulus tectus (Cook, 1897), specimen from Cameroon (A–C) A. Anterior gonopods, anterior view. B. Anterior gonopods, posterior view. C. Left posterior gonopod, anterior view. Abbreviations: cx = coxa, lo = apical lobe of telopodite, sf = sigmoid flange of telopodite, st = sternum, tlp = telopodite. Scale bars = 1 mm.

FIGURE 5. Pelmatoiulus spp., left posterior gonopod. A, B: P. tectus (Cook, 1897), male from Cameroon. C, D: P. togoensis (Cook, 1897), male from Ghana. A, C: anterior view. B, D: apical lobe with efferent canal. Abbreviations: al = apical lobe, cn = constriction, eg = efferent groove, pr = basal process, sa = striate area, sl = subapical lobe. Scale bars: 1 mm (A, B), 0.5 mm (B, D).

FIGURE 6. Right vulva of Pelmatojulus tectus (Cook, 1897), specimen from Cameroon. A. ventral view. B. lateral view. C. anterior-ventral view. D.posterior view. Abbreviations: lb = lobe of lateral valve, lv = lateral valve, mv = mesal valve, op = operculum. Scale bars = 0.5 cm (A, B), 0.2 mm (C, D).

FIGURE 7. Records of Pelmatojulus spp. from Cameroon.