Parabolus dimorphus ( Carl, 1909 ) Carl, 1909

Enghoff, Henrik, 2011, East African giant millipedes of the tribe Pachybolini (Diplopoda, Spirobolida, Pachybolidae), Zootaxa 2753, pp. 1-41 : 24-25

Parabolus dimorphus ( Carl, 1909) , n.comb.

( Figs 44–53 , 84 )

Trigoniulus dimorphus Carl, 1909

Pachybolus dimorphus: Hoffman (1965)

SYNTYPES: 2 3, 1 Ƥ TANZANIA, Dar-es-Salaam, 6°50’S 39°20’E, J. Carl leg. (MHNG).

ADDITIONAL MATERIAL: 1 Ƥ, 1 subadult Ƥ TANZANIA, Dar-es-Salaam (ZMUH). – 1 3 “Deutsch Ost- Afrika” 1903, F. Eichelbaum leg., R.L. Hoffman det., 1964 (ZMUH). – 1 3 “Ost-Afrika”, plantations and roads in vicinity of Dar-es-Salaam, 1929, H. Brinkmann leg, R.L. Hoffman det., 1964 (ZMUH).

Notes to the material. The type series ( MHNG) contains two 3 and one Ƥ. Since they were all in the same container, and the gonopods of both 3 had been dissected, it was not possible to associate the two sets of gonopods (one of which lacks one of the posterior gonopods) with the two male bodies. The latter could be reconstructed based on Carl’s information about body ring number (“57 Segmente”). Each of the three individuals has now been placed in a separate container, and the two sets of gonopods in two further, separate containers. The two 3 are obviously conspecific, and given the uncertainty about which gonopods belong to which body, I have not selected a lectotype. The female and subadult female from Dar-es-Salaam ( ZMUH) are labelled as paratypes and listed as “Paratypoid” by Weidner (1960), but it is uncertain if they belong to the material studied by Carl (1909) who did not indicate how many specimens he had studied; the hand-writing on the label is different from that on the type-vial label.

Diagnosis. A species of Parabolus in which the anterior gonopod coxa has no distinct distolateral shoulder and the terminal segment of the posterior gonopod has a coarsely serrated mesobasal lobe and a slender, curved, blunt apical process

Descriptive notes. Carl’s original description is quite good. In particular, his illustrations are fine and are reproduced here as Figs 44–46 .

As Crurifarcimen vagans except:

- Adults with 56 podous rings, no apodous rings. Length ca. 12 cm. Width: 11.9–12.4 mm (3) / 11.9–12.2 mm (Ƥ). Ten rows of ocelli in 5–6 horizontal series.

- 2+2 labral teeth, one 3 with ca. 10+10 labral setae in bight above labral teeth, other specimens without setae.

- Mandibles with 4 pectinate lamellae plus a variable number of teeth in a jumbled group basally; ventral margin of gnathal lobe pectinate area not concave; a sclerotized smooth-edged ridge between pectinate lamellae and mola, ridge dorsally with a row of small spines; 5 molar ridges.

- Gnathohilarium with 3+3 distal stipital and 4–5+4–5 distal lingual lamellar setae in transverse row.

- Collum smooth, no striae, with more or less marked marginal furrow at anterior margin.

- Body rings: tergo-pleural suture visible on pro-, meso- and metazonite.

- Terga smooth, except for fine oblique striae ventrally on mesozona and fine, dense longitudinal striae on metazona.

- Ozopores 1 diameter in front of suture.

- Telson as in Crurifarcimen v. but dorsal profile straight.

- Legs. Length 63% of body width.

Male sexual characters. Leg modifications as in C. vagans . The coxal lobes on legs 6–7 were not mentioned by Carl (1909). In the two males of the type series, these legs are badly damaged, but in the males from ZMUH, the lobes are evident.

Anterior gonopods ( Figs 45–48 ): sternum concave on oral face, with high, broad, triangular mesal process reaching ca. 2/3 the height of the coxae; two halves of process meeting under blunt angle in midline, forming a midline ridge; tip of process with small median indentation; sternum laterally continuing as narrow band around side of gonopod, reaching well along base of coxa on aboral side, articulating with a narrow sclerite at base of telopodite (“ bridetrachéenne” of Demange 1967). Coxa in oral view kidney- to sausage-shaped, lateral margins evenly convex, mesally with very big slender process directed distad parallel to mesal margin of main part of coxa; internal surface of coxa (hidden from view in undissected specimens) with ridge at base of mesal process. Coxa extending to aboral side of gonopod where it appears as a narrow lateral band. Telopodite ( Fig 48 ) extending slightly beyond coxal tip, with a distolateral incision and a shallow impression running from incision to base of low mesal process which very slightly overlaps that of opposite telopodite; tip of telopodite distally broadly rounded; oral surface of telopodite (hidden from view in undissected specimens) with strong, oblique ridge delimiting a narrow furrow.

Posterior gonopods ( Figs 44 , 49–50 ) in situ supported by ridge at base of mesal coxal process and oblique ridge on oral surface of telopodite of anterior gonopod; visible in oral and aboral view as narrow bands along mesal margin of coxa and telopodite, respectively, connected by median sternal remnant consisting of mesal membranous region flanked by a pair of rounded-triangular sclerites. Each posterior gonopod clearly divisible into four parts:

1. a long, slender, almost straight tracheal apodeme, flattened towards its end,

2. a basal sclerite which articulates with the tracheal apodeme, is roughly pentagonal in outline and has a distinct notch on its distal margin, next to articulation with median sternal sclerite,

3. an intermediate segment originating from lateral half of basal sclerite, parallel-sided, with extensive membranous areas, especially on mesal part of aboral surface,

4. a terminal segment separated from intermediate segment by distinct impression across lateral and aboral surface. Overall shape of terminal segment triangular (or like the profile of a hadrosaur head); with a small laterobasal, stout spine at articulation with intermediate segment, a coarsely serrate mesobasal lobe resting (in situ) on convex ridge at base of mesal coxal process and a slender, curved, apically clublike rounded process; aboral surface smooth, oral surface with a longitudinal keel running from base to tip. Efferent groove running along mesal edge of intermediate segment, then making an abrupt turn and terminating behind longitudinal keel of terminal segment.

Female sexual characters. Distal margin of lateral coxosternal extensions projecting as right-angled lobe.

Vulva ( Figs 51–53 ) less elongate than in Crurifarcimen vagans , valves quite regularly sub-ovoid in shape, with free

margins only very shallowly sinuous, oral valve much longer than aboral valve, with large, rounded-subpyramidal

apical appendix ( Fig. 53 ) in situ lying close to lateral coxosternal extension. Crest not protruding.

Distribution. Only known from Dar-es-Salaam, Tanzania ( Fig. 84 ).

Figures

FIGURE 84. Known distribution of East African Pachybolini, except Hadrobolus crassicollis and Epibolus pulchripes. dots (●): Crurifarcimen vagans, filled diamonds (♦): Hyperbolus apicomplexus, open diamonds (♢): Hyperbolus morogoroensis, filled triangle (˔): Parabolus dimorphus, inverted open triangle (): Parabolus calceus, inverted filled triangle (ˑ): Pachybolus tectus,, filled square (․): Pachybolini indet. Based on Yahoo maps.

FIGURES 44 – 46. Parabolus dimorphus, original drawings from Carl (1909), original labelling removed. 44: right posterior gonopod, anterior view, 45: left anterior gonopod + anterior gonopod sternum, anterior view, 46: anterior gonopods, posterior view. tr. a.: tracheal apodeme.

FIGURES 47 – 50. Parabolus dimorphus. 47: male from the vicinity of Dar-es-Salaam, Brinkmann leg., gonopods (without left anterior gonopod coxa and telopodite), anterior view, 48: do., posterior view, 49: male from ” Deutsch Ost-Afrika ”, Eichelbaum leg., right posterior gonopod, anterior view, 50: do., posterior view. Scales 2 cm. acp: apical clublike process, bs: basal sclerite, cx: coxa, is: intermedite segment, k: keel, sl: serrate lobe, st: sternum, tlp: telopodite.

FIGURES 51 – 53. Parabolus dimorphus, female from the vicinity of Dar-es-Salaam, Brinkmann leg., right vulva. 51: posteriolateral view, 52: basis of vulva with operculum; 53, apical appendix. Scales: 1 mm (51), 0.1 mm (52 – 53). ap: apical appendix, op: operculum. SEM.