Sphaerobelum, Verhoeff, 1924

Wesener, Thomas, 2019, First records of giant pill-millipedes from Laos (Diplopoda, Sphaerotheriida, Zephroniidae), Zootaxa 4563 (2), pp. 201-248 : 239-240

Sphaerobelum sp. L10

Material examined: 1 F (SMF) from Laos, Vientiane Province, Vang Vieng, W. of Nam Song (N18°55'46.86", 102°20'56.82"E), 324 m, Tham Nam Or Khem, in front of cave; leg. by hand, 28.VII.2014, P. Jäger & S. Münnich.

Unique characters: Brown species, tergites covered by pits. Anal shield without locking carinae. Legs unmodified with surprisingly few ventral spines ( Fig. 25B ). Operculum of vulva on protruding up to basal 1/5 of prefemur, mesally extended ( Fig. 25C ). Coxa 2 with a weakly developed process ( Fig. 26C ).

Description: Measurements: Body length ca 24.7 mm. Width, of thoracic shield = 14.6 mm. Height, of thoracic shield = 8.2 mm. Coloration: in preserved specimen light brown. Head and collum slightly darker brown. Antennae and legs light brown.

Head: Eyes with ca. 55 ocelli. Last antennomere thickened. Apical disc with 38/39 apical cones. All antennomeres covered by long setae. Organ of Tömösváry located inside antennal groove. Gnathochilarium: structure typical of the order. Palpi sensory cones in several clusters. Mandibles: not dissected.

Stigmatic plates: first stigmatic plate widely rounded, apex well-rounded, slightly curved towards coxa 1 ( Fig. 26A ). Laterotergites: laterotergite 1 and 2 slightly elongated into a short, broad process. Collum: with glabrous surface, margins with few isolated setae. Thoracic shield: surface glabrous, but covered with small pits like tergites, setae only in grooves. Shallow grooves beset with numerous long setae, slope towards groove without keels. Tergites: glabrous, but entirely covered by tiny pits. Tips of paratergites of midbody tergites projecting posteriorly. Anal shield: slightly flattened. Underside without locking carinae. Legs: leg-pair 1 with 2 ventral spines, leg-pair 2 with 3 or 4, leg-pair 3 with 5. First two leg-pairs without an apical spine. Leg-pairs 4–21 with 6 ventral spines and one dorso-apical spine. In leg 9 femur 1.8 times, tarsus 4.6 times longer than wide ( Fig. 26B ). All podomeres densely setose. Coxa with a well rounded process. Coxa process absent at first leg ( Fig. 26A ) and weakly developed at second ( Fig. 26C ).

Female sexual characters: Vulva small, covering mesal half of coxa, extending mesally to anterior fifth of prefemur ( Fig. 26C ). Operculum rounded, mesal margin strongly projecting into a well-rounded lobe twice as high as remaining operculum. Subanal plate: large and wide, undivided, central margin slightly recessed. Densely setose ( Fig. 26D ).

Figures

FIGURE 25. Sphaerobelum schwendingeri n. sp. A–C female paratype (ZMUC), D–G male holotype (MHNG). A: coxa of first right leg with first stigmatic plate; B: 9th left leg; C: coxa and prefemur of second leg with vulva; D: left anterior telopod, anterior view; E: left anterior telopod, posterior view; F: right posterior telopod, anterior view; G: right posterior telopod, posterior view. Abbreviations: Cx = coxa; O = operculum of vulva; Pre = prefemur; St-Pl = stigmatic plate; Syn-Cx = syncoxite. Scale bars = 1 mm.

FIGURE 26. Sphaerobelum sp. L10 (SMF); A: coxa of first left leg with first stigmatic plate; B: 9th left leg; C: coxa and prefemur of second leg with vulva; D: subanal plate. Abbreviations: Cx = coxa; O = operculum of vulva; Pre = prefemur; St-Pl = stigmatic plate. Scale bars = 1 mm.