Figs 12A–C, F–I with Figs 2N–S). External characters support this assignment: dorsal setae are simple and cut-off apically (compare Fig. 12K with Fig. 2d), elytra lack longitudinal striae except for sutural stria, and pronotum and elytra are yellowish in color. The specimens above seem to stand close to the Argentinian species C. argentina Miller, 1974 and C. hermani Miller, 1974 of the C. atra group defined by MILLER (1974). When compared with the genitalia drawings and descriptions provided by MILLER (1974) it seems that the specimens examined here represent an undescribed species. We are however leaving it undescribed, as it is likely introduced and a more detailed comparison with the American species would be necessary to diagnose the species properly. The presence of the species which is clearly an element of Neotropical fauna in Saudi Arabia is very unexpected. The first author discussed the problem with both collectors (J. Bezděk and D. Král) and with the person who

Published as part of Fikáček, Martin & Liu, Hsing-Che, 2019, A review of Thysanarthria with description of seven new species and comments on its relationship to Chaetarthria (Hydrophilidae: Chaetarthriini), pp. 229-252 in Acta Entomologica Musei Nationalis Pragae 59 (1) on page 251, DOI: 10.2478/aemnp-2019-0020, http://zenodo.org/record/4488918