New nematode species and genera (Nematoda: Chromadorea) from cold seeps on Hikurangi Margin, New Zealand Author Leduc, Daniel National Institute of Water and Atmospheric Research, Wellington, 14 - 901, New Zealand. daniel.leduc@niwa.co.nz text European Journal of Taxonomy 2023 2023-01-10 856 1 45 http://dx.doi.org/10.5852/ejt.2023.856.2025 journal article 223185 10.5852/ejt.2023.856.2025 f565e591-f14b-437d-9a18-071194a6a53e 2118-9773 7522913 1EF03A88-7A30-4CAB-822C-9911BCF38601 Family Xyalidae Chitwood, 1951 Diagnosis (from Fonseca & Bezerra 2014 ) Cuticle striated. Six outer labial setae and four cephalic setae in one circle, with cephalic setae shorter than or at most equal to outer labial setae. Often additional setae and occasionally eight groups of subcephalic setae present. Buccal cavity usually funnel-shaped, completely or only at the base surrounded by pharyngeal tissue. Ventral gland mostly absent. Females with one anterior ovary to the left of intestine. Males usually with two testes, the anterior one to the left of intestine, the posterior one to the right of intestine (or absent). Remarks A list of valid genera and species of the family Xyalidae was provided by Venekey et al . (2014) . The Xyalidae is a large and diverse family of nematodes currently comprising 50 valid genera ( Venekey et al . 2014 ; Jiang & Huang 2015 ; Leduc 2015 ; Yu & Xu 2015 ; Gagarin 2020 ).