Key to all known species of Pseudonchus 1 Male amphideal fovea 30% of cbd or less................................................................. 2 - Male amphideal fovea more than 30% of cbd.............................................................. 4 2 Male with pre-cloacal supplements...................................................................... 3 - Male with no supplement or genital setae.............................................. P. kosswigi Murphy, 1964 a 3 Male with prominent swollen pre-cloacal supplements and genital setae................ P. symmetricus De Coninck, 1942 - Male with pre-cloacal ventral ala and 7–10 tubular pre-cloacal supplements................... P. j e n s e n i Murphy, 1964b 4 Male amphideal fovea circular or cryptocircular............................................................ 5 - Male amphideal fovea unispiral or multispiral............................................................. 6 5 Male amphideal fovea circular, body slender (a = 50), one large double-jointed pre-cloacal papilla............................................................................................... P. northumbriensis Warwick, 1969 - Male amphideal fovea cryptocircular, body stout (a = 20), five short pre-cloacal setae.................. P. virginiae sp. n. 6 Male amphideal fovea multispiral................................................. P. rotundicephalus Cobb, 1920 - Male amphideal fovea unispiral......................................................................... 7 7 Male with tubular pre-cloacal supplements, spicules with rounded capitulum..................................... 8 - Male with no supplements, spicules with squared capitulum.................. P. gerlachi (Gerlach, 1953) Warwick, 1969 8 Cephalic setae> 10 Μm long, caudal setae present........................................................... 9 - Cephalic setae 3.0 mm, tail ~2 abd long............................................. P. pachysetosus Blome, 1982

Published as part of Leduc, Daniel & Verschelde, Dominick, 2013, One new genus and two new free-living nematode species (Desmodorida, Desmodoridae) from the continental margin of New Zealand, Southwest Pacific Ocean, pp. 274-290 in Zootaxa 3609 (3) on page 288, DOI: 10.11646/zootaxa.3609.3.2, http://zenodo.org/record/216636