Plectrogonodesmus gounellei (Brölemann), Hoffman, 2012

Hoffman, Richard L., 2012, New Genera For Two Poorly-Known Millipeds From Bahia (Polydesmida: Chelodesmidae), Papéis Avulsos de Zoologia 52 (8), pp. 103-110 : 103-110

Plectrogonodesmus gounellei (Brölemann)

comb. nov.

Figures 1-7

Leptodesmus Gounellei Brölemann, 1903, Ann. Soc. Entom. France, 71:665, text figs. 17, 18, pl. 7, figs. 16-18. Male holotype (Mus. Hist. Nat. Paris) from “ Santo Antonio da Barra, Sertão de Bahia ”, E. Gounelle, leg.

Pseudoleptodesmus (Pseudoleptodesmus) gounellei : Attems, 1931, Zoologica, 30(79):27.

Leptodesmus (Pseudoleptodesmus) gounellei : Attems, 1938, Das Tierreich, 69:40, fig. 43.

Leptodesmus gounellei : Schubart, 1946, An. Acad. Brasileira Cienc., 18:195 (listed only).

Material: The holotype has been examined. Diagnosis: With the characters of the genus, further specific characters may be distinguished in the configuration of the gonopods when additional species are discovered.

Description (abstracted from original text): Body large, length 68 mm, width of 3 rd tergum, 10.8 mm, of 9 th tergum, 10.8 mm (prozonal diameter 6.8 mm) sides of body parallel, abruptly narrowed posteriad.

Very dark reddish brown, almost black, with the peritreme and adjacent surface of the paranotum yellow.

Head somewhat shiny, divided by a well-defined suture extending between the antennae, and bearing up to their level a weak subtriangular depression. Antennae very long (12 mm) and slender, exceeding the posterior border of the 3 rd paranotum, not reflexed distally, antennomeres long and slender.

Collum much wider than the head, almost as broad as the following tergum, anterior border weakly arcuate medially, lateral ends narrowed to acute angle. Surface of metaterga dull, without transverse sulcus or seriate tubercles. Paranota well developed, placed at midheight of segments, a little declivous, continuing convexity of metaterga. Anterior corners broadly rounded, posterior obtusely rounded on anterior segments, becoming right-angled at midbody and increasingly acutely produced in going posteriad. Ozopores located in the posterior third of marginal peritremata, which form the posterior paranotal corner on all segments, and virtually the entire paranotum on segment 19 ( Fig. 1 ).

Sterna broad, slightly elevated, with two paramedian projections between the posterior legpair of each postgonopodal segment ( Fig. 2 ), anterior surface sparsely setose. Legs long and slender, the tibiae without apical subtarsal pads; pregonopodal legs without modifications. Sternum of segment 4 with two contiguous long processes ( Fig. 3 ), sternum of segment 6 deeply concave for accommodation of the gonopodal apices. Gonopod aperture ( Fig. 4 ) large, transversely oval, extending nearly to anterior edge of segment 7, and caudad between the 8 th pair of legs, posterior edge of aperture extended shelf-like into the cavity, this surface with several ridges in front of each coxa.

Gonopods notably large, coxae extended outside aperture rims, a large heavily sclerotized mesosternum; coxosternal apodeme elements nearly straight, elongated, apically a little enlarged. Coxa strongly prolonged on the lateral side ( Fig. 7 ); a dorsal field of setae; no paracannular setae. Base of telopodite (prefemur) continuing main coxal axis, thence curved anteriad into a long very slender acropodite region, with small triangular apical lobe; efferent duct visible for its entire length in mesal aspect, carried by a slender acuminate solenomere. Acropodite region paralleled by a long slender prefemoral process, slightly broadened distally, with serrate edges. Neither acropodite nor prefemoral process with cingulum.

Comments: When visited by Gounelle in 1889, Santo Antonio da Barra was the name used for the city now called Condeúba in southwestern Bahia (14.53.35S, 41.59W) .

Figures

FIGURES 1‑4: Plectrogonodesmus gounellei (Brölemann), peripheral structures. 1. Posterior end of body, right side, segments 17-20. 2. Sternum of segment 16, anteroventral aspect. 3. Sternal region of segment 4 and coxae of 3rd pair of legs. 4. Gonopod aperture and sternal region of segment 7.

FIGURES 5‑7: Plectrogonodesmus gounellei (Brölemann), male genitalia. 5. Coxa and median sternal sclerite of right gonopod, anterior aspect. 6. Left gonopod, mesal aspect. S, solenomere. 7. Coxa and base of telopodite of left gonopod, lateral aspect.