Two new species of penicillate millipedes (Diplopoda, Polyxenidae) from Phu Quoc Island in southern Vietnam Author Huynh, Cuong text Zootaxa 2018 2018-03-28 4402 2 283 302 journal article 30402 10.11646/zootaxa.4402.2.3 7139708e-922d-41d4-ad42-a5d5f7076f1a 1175-5326 CEA5700E-9F94-42A8-9067-BD8F4D301B9D Genus Unixenus Jones, 1944 Monoxenus Jones, 1937: 138 ; Silvestri 1948: 216 . Unixenus Jones, 1944: 94 ; Nguyen Duy-Jacquemin and Condé 1967: 68 . Type species: Unixenus padmanabhai ( Jones, 1937 ) Diagnosis. Body with 10 segments, 9 pleural projections and a telson, 13 pairs of legs. Eight ommatidia in each eye; 8 antennal articles with the article VI longest and the article VIII shortest with 4 sensory cones present. Antennal article VI commonly with 1 setiform sensillum between 2 thick bacilliform sensilla, and 1 conical sensillum posteriorly. Anterior surface of labrum covered with spherical papillae gradually reducing in size posteriorly. Lateral palp of gnathochilarium 1.5–2.5 times longer than medial palp, 20–22 sensilla on medial palp and 13 on lateral palp. Two or more rows of tergal trichomes arranged in two latero-posterior clusters either side of the midline, with a central gap. Anterior row often uneven, intermediate rows rarely in defined rows and posterior row of trichomes continuous or with a medial gap. Tarsus 2 with a setiform seta. A single caudal bundle containing caudal trichomes with 1–11 hooks.