Cienfuegia gen. nov. (Xyalidae) and Pseudoterschellingia gen. nov. (Linhomoeidae), two new genera of free‐living marine nematodes from the Caribbean Sea

Two new genera of nematodes are described from the Caribbean Sea. Cienfuegia gen. nov. belongs to the Xyalidae based on the position of the anterior gonad constantly left of the intestine, cuticle clearly striated, second and third circle of anterior sensilla inserted at the same level and buccal cavity surrounded by pharynx. The new genus is differentiated from other genera by the buccal cavity divided in two chambers and by the four cephalic setae being longer than the six outer labial setae. Within the Xyalidae, Cienfuegia shows most affinities with the genera Daptonema and Theristus. Pseudoterschellingia gen. nov. is placed within the Linhomoeidae on the basis of the presence of anterior rounded amphidial fovea, unarmed narrow buccal cavity, distinctive cardia and presence of apophysis of gubernaculum. Pseudoterschellingia is closely related to the genera Terschellingia and Terschellingioides, but is differentiated by the crypto‐spiral amphidial fovea, and conical buccal cavity surrounded by pharyngeal tissue.