Onomeris

Wesener, Thomas, 2010, Revision of the American Pill Millipedes I: Onomeris and Trichomeris (Diplopoda, Glomerida, Glomeridae), Zootaxa 2725, pp. 28-40 : 32-33

Key to the species of Onomeris

The pill millipede fauna of America is still relatively little known. Careful examination of the telopods of any Glomerida specimen found in America is therefore necessary to identify the species. For example, an undescribed genus co-occurs with O. sinuata and has similar colouration and size. Additional undescribed Glomerida species probably occur in the eastern United States.

1. Posterior margin of anal shield in males medially strongly concave ( Fig. 5 E). Tibial process of telopod slender, not tapering towards tip; tibia without trichostele ( Fig. 5 B)............................................................... 2

- Posterior margin of anal shield in males medially only very weakly concave. Tibial process of telopod triangular, basally wide, apically tapering; tibia with trichostele ( Figs 7 C, D). Cumberland Plateau, NW Alabama to Virginia............. O. sinuata

2. Syncoxital lobe of telopod subtrapeziform ( Fig. 3 B). Third antennomere 2x as long as second, sixth antennomere 2.1 times longer than wide ( Fig. 1 A). Known from Alabama, Georgia and Mississippi............................ O. underwoodi

- Syncoxital lobe of telopod bilobed ( Fig. 6 C). Third antennomere 1.5x as long as second, sixth antennomere 2.5 times longer than wide. Known from Virginia, Georgia and North Carolina......................................... O. australora

Figures

FIGURE 1. Onomeris underwoodi Cook, 1896 (FMNH-INS 14113) SEM. A: head, left antenna removed; B: thoracic shield (2 nd tergite), lateral view; C: Collum (1 st tergite); D: Gnathochilarium, underside, overview; E: Gnathochilarium, central pads and endochilarium, detail; F: Organ of Tömösváry. Abbreviations: 4 AS = 4 apical cones of the antenna; A 1 – A 6 = antennomeres; AG = antennal groove; cCO = central sensory cones; cP = central pads of endochilarium (rudimentary median palps?); Cr = Y-shaped crest; Imp = impression in front of schism; IP = inner palps; L = labrum; lCo = lateral sensory cones of endochilarium; LP = lateral palps; m-str = marginal stria; O 1 – O 5 = ocelli; Schi = schism; str = striae; TO = organ of Tömösváry.

FIGURE 3. Onomeris underwoodi Cook, 1896 (FMNH-INS 14113) SEM. A: 18 th leg of male, anterior view; B: telopod (19 th leg), posterior view. Abbreviations: 1 – 4 = # of podomeres; cl = central lobe of syncoxite; Cx = coxa; IH = inner horns; scl-t = sclerotized teeth.

FIGURE 5. Onomeris underwoodi Cook, 1896, lectotype (USNM [NMNH] 2599). A: left telopod (19 th leg), anterior view; B: right telopod, posterior view; C: left telopod, posterior view; D: rudimentary male 17 th leg, anterior view; E: male anal shield, view from behind. Abbreviations: scl-t = sclerotized teeth. Scale bars = 1 mm.

FIGURE 6. Onomeris australora Hoffman, 1950, male syntype (USNM [NMNH] 1872). A: male anal shield, view from behind; B: rudimentary male 17 th leg, anterior view; C: right telopod, anterior view; D: right telopod, posterior view. Abbreviations: scl-t = sclerotized teeth. Scale bars = 1 mm.

FIGURE 7. Onomeris sinuata (Loomis, 1943) n. comb. topotype (FMNH-INS 56316). A: rudimentary male 17 th leg, anterior view; B: 18 th leg of male; C: telopod pair, anterior view; D: left telopod, posterior view. Scale bars = 1 mm.