Cienfuegia gen. nov. (Xyalidae) and Pseudoterschellingia gen. nov. (Linhomoeidae), two new genera of free-living marine nematodes from the Caribbean Sea Author Armenteros, Maickel Author Vincx, Magda Author Decraemer, Wilfrida text Journal of Natural History 2009 2009-05-31 43 17 - 18 1067 1081 http://dx.doi.org/10.1080/00222930902767466 journal article 10.1080/00222930902767466 1464-5262 4590565 Genus Pseudoterschellingia gen. nov. Etymology The genus closely resembles in morphological features the genera Terschellingia de Man 1888 and Terschellingioides Timm 1967 and therefore we propose the combination of pseudo (5false) and Terschellingia . Diagnosis Linhomoeidae . Cuticle transversely striated; amphidial fovea crypto-spiral with one loop, located relatively far anteriorly in the head region, buccal cavity narrow and conical, surrounded by pharyngeal tissue and without teeth or other cuticularized structures; pharynx with rounded muscular posterior bulb, cardia small, narrow triangular, surrounded by intestine and pericardial cells; males monorchic, spicules curved and strongly cuticularized; females monodelphic, ovary outstretched to the left of intestine; tail conico-cylindrical with spinneret and without terminal setae. Type species Pseudoterschellingia ibarrae gen. nov., sp. nov. Discussion and relationships Within the order Monhysterida, Lorenzen (1994) did not find any holapomorphy for the superfamily Siphonolaimoidea . Several features suggest that P. ibarrae belongs to this superfamily: (1) the monodelphic–prodelphic condition for females and the monorchic condition for males, (2) the existence of pharyngeal glands (visible in some specimens), (3) the presence of pharyngeal posterior bulb (difference with Monhysteroidea and Axonolaimoidea), (4) intestinal turgent cells, (5) second and third circle of cephalic sensilla clearly separated (difference from most Monhysteroidea ), and (6) absence of preanal papillae (difference from most Axonolaimoidea). The superfamily Siphonolaimoidea is composed of the families Siphonolaimidae and Linhomoeidae . Pseudoterschellingia gen. nov. can be clearly differentiated from most genera within the Linhomoeidae by buccal cavity narrow and unarmed compared with a wider buccal cavity with the presence of some kind of sclerotized structures like teeth or arches; the crypto-spiral shape of amphidial fovea vs. circular; and the size and shape of cardia: small and triangular vs. well-developed and elongated. From the 22 valid genera within Linhomoeidae , Pseudoterschellingia gen. nov. shows the highest affinities with the genera Terschellingia de Man 1888 and Terschellingioides Timm 1967 ; shared and differentiating features are presented in Table 3 .