An unusual new ceramonematid, Ceramonema nasobema sp. n., is described using light and scanning electron microscopy.
It is particularly characterised by the presence of a perioral tube projecting 5.5-7.0 ìm anterior to the lips, moderately long body (0.86-
1.09 mm), relatively small number of body annules (121-134), weakly developed zygapophyses, absence of intracuticular vacuoles,
pronounced sexual dimorphism in amphid shape with the male ventral amphidial branch extending as far posterior as the 55-80th
annule (no extension in females), barrel-shaped stoma, sigmoid and anteriorly inclined vagina without sclerotisations, gubernaculum
with dorsal apophyses and relatively uniform cloacal annules. The new species differs from all other known species of Ceramonema
especially by the shape of the amphid in males, the strongly projecting perioral tube and the inclined, sigmoid, vagina. Additional data
on morphology of Ceramonema algoensis (from Natal Bay, South Africa) are also provided as this species has the most prominent
perioral tube among previously described members of the genus.