The morphology and morphometry of nematodes of six species of the family Ceramonematidae is described using light and
scanning electron microscopy. In this paper, we describe two new species and redescribe two known species of Ceramonema and one
new species each of Pselionema and Pterygonema. Ceramonema altogolfi sp. n. is characterised by the 0.8-1.3 mm long body, 187-247
body annules, weakly developed zygapophyses, presence of intracuticular vacuoles, sexual dimorphism in amphid shape, presence of
vaginal sclerotisation, complex gubernaculum and relatively uniform anal and cloacal annules, whilst C. inguinispina sp. n. has a 0.8-
1.1 mm long body, 135-191 body annules, weakly developed zygapophyses, presence of intracuticular vacuoles, sexual dimorphism
in amphid shape, absence of vaginal sclerotisation, thorn-shaped precloacal projection, plate-like gubernaculum and double cloacal
annule. Pselionema psednum sp. n. is distinguished by 1.4-1.7 mm long body, 251-292 body annules, weakly developed zygapophyses,
absence of intracuticular vacuoles, sexual dimorphism in amphid shape and Pterygonema mexicanum sp. n. is characterised by having
amphids lacking a central thorn-like projection and pharynx with a distinct posterior glandular bulb. Populations of Ceramonema rectum
and Ceramonema cf. yunfengi are also described. The male cloacal region of the species examined appears to be a rich potential source
of taxonomic characters that have as yet received insufficient attention for this family.
Keywords – Baja California, Ceramonema altogolfi sp. n., Ceramonema inguinispina