Onomeris underwoodi Cook 1896
Creators: name: Wesener, Thomas
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Glomerida
Glomeridae
Onomeris
Onomeris underwoodi

description: Onomeris underwoodi Cook, 1896
(Figures 1–3, 5)
O. underwoodi Cook, 1896: 43
Hoffman 1950: 14; Chamberlin & Hoffman 1958: 12; Hoffman 1999: 18 (list species name).
Material examined: Type material: 1 male lectotype (designated by Dr. R.L. Hoffman),> 120 male and female paratypes (USNM [NMNH] 2599). U.S.A., Alabama, Lee County, Auburn.
Other material examined: 2 M, 1 F (FMNH-INS 14133). U.S.A., Mississippi, Harrison County, Harrison Expt. For., coll. D. Beyers & M. Jenks, in black cherry tree hole, 29.iii.1984; 1 M, (FMNH-INS 56301). U.S.A., Alabama, Jackson County, 5 miles NE Garth, coll. S. Peck, 19.v.1972; 6 M, 4 F (FMNH-INS 56299). U.S.A., Georgia, Effingham County, Kildare, leg. L. Hubricht, 03.x.1959, det. Hoffman; 1 M, 1 F (FMNH-INS 56303). U.S.A., Alabama, Shelby County, Oak Mountain State Park, coll. H. S. Steenes, 16.x.1960; 13 M, 6 F (VMNH). U.S.A., Tennessee, Polk County, Hiawassee River bluff, 2.7 miles NW Reliance, coll. C. Hubricht, 14.V.1961; 2 M, 2 F (VMNH). U.S.A., Tennessee, Blount County, Chilhowee Mountain, Foothills Parkway, 3.5 miles SW Walland, coll. C. Hubricht, 23.IX.1967.
Locality from the literature: N. to Kentucky (Hoffman 1999)
Diagnosis: Differs from O. sinuata n. comb. in absence of a trichostele on the tibia of the telopod (Fig. 5 A), tibial process slender (Fig. 5 B); the presence of larger coxal lobes on the 17th leg pair of the male (Fig. 2 B), presence of 5+1 black ocelli (Fig. 1 A), and anal shield obviously concave medially at caudal edge (Fig. 5 E). Differs from O. australora in syncoxital lobe of telopod not divided into two lobes (Fig. 3 B), third antennomere 2x second (Fig. 1 A), sixth antennomere 4x second (Fig. 1 A), 2.1 times longer than wide, three striae crossing thoracic shield dorsally (Fig. 1 B).
Redescription: Length of non-stretched but unrolled specimens of both sexes ca 4–5 mm, width 2.2–2.8 mm, respectively.
General coloration strongly faded in alcohol, dark, brown to greyish, often with contrastingly lighter markings on the lateral part of the tergites. Legs, antennae and lateral parts of head grey.
Antenna: third antennomere as large as first and second combined, sixth antennomere as large as first, second, fourth and fifth combined, the latter 2.1 times longer than wide.
Male anal shield at posterior margin medially strongly concave (Fig. 5 E).
Male 17th leg with strongly developed coxal lobe (Fig. 5 D).
Telopod as in the genus description, with slender tibial process and subtrapeziform subcoxital lobe (Figs 3 B, 5A–C).
Intraspecific variation: Since the shape of the male telopod, especially those of the tibial process (difference from O. sinuata) and the subcoxital lobe (difference from O. australora) are important taxonomic characters, these structures were studied in 25 males of the extensive type series and 20 non-type males. No differences in the telopod shape could be observed. Only the shape of the femoral process shows a very high variation, probably because of the membranous nature of this structure.
Comments: The telopods and other characters of this species were not properly described (Cook 1896) and never redescribed, leading to confusion about the status of the species (Hoffman 1950), or even the genus (Mauriès 2005).
description: Published as part of Wesener, Thomas, 2010, Revision of the American Pill Millipedes I: Onomeris and Trichomeris (Diplopoda, Glomerida, Glomeridae), pp. 28-40 in Zootaxa 2725 on page 33, DOI: 10.5281/zenodo.199966