Enchodelus vestibulifer Altherr 1952

Enchodelus vestibulifer Altherr, 1952 Enchodelus vestibulifer Altherr, 1952; Altherr (1952) BLR: https://doi.org/10.5281/zenodo.10813922 Enchodelus vestibulifer; Meyl (1961) BLR: https://doi.org/10.5281/zenodo.11015551 Enchodelus vestibulifer; Eliava and Eliashvily (1990): 68,102 BLR: https://doi.org/10.5281/zenodo.11003031 Enchodelus vestibulifer; Peña-Santiago (2021 b): 211 Description Material examined. One female in poor condition, mounted on one slide labelled Enchodelus vestibulifer n. sp., and collected from Parc National, st. 39 in July 1948 (Fig. 1). Measurements: L = 1.36 mm, a = 32.4, b = 3.8, c = 61.8, c’ = 1.0, V = 53 %, neck length = 355 µm (Fig. 5). Habitus curved ventrally after fixation, adopting an open C-shape (Fig. 6). Cuticle consisting of two layers, its outer layer provided with distinct transverse striations. Lip region 16 µm wide, offset by a shallow depression (Fig. 7). Cheilostom a wide cavity. Amphidial fovea funnel shape. Odontostyle 24 µm long, strong with wide lumen, straight, 1.5 times lip region diameter, 1.8 % of body length. Guiding ring double. Anterior region of pharynx enlarging gradually; pharyngeal basal expansion 174 µm, occupying about half of total neck length, bearing muscular sheath (Fig. 8). Pharyngeal gland nuclei not visible, their orifices obscure. Cardia rounded. A disc-like structure separating the pharyngeal base from cardia present. Female genital system diovarian. Uteri not differentiated. Vagina extending inwards for 62 % of body diameter, pars refringens vaginae not well preserved (Fig. 9). Prerectum 1.4, rectum 1.3 times anal body diameter long. Tail conical with rounded tip, 22 µm long, 1.8 % of body length (Fig. 10). Distribution This species is a part of Palearctic nematode fauna, currently known only from Switzerland (type habitat: soil of grasses; 1900 m a. s. l. - Altherr (1952)). Taxon discussion Altherr (1952) described this species on the basis of a single female from Switzerland and no later record exists. The female forms part of Altherr’s collection, deposited in the Museo Cantonale di Storia Natu rale di Lugano (Switzerland). Its state of preservation is not good, so that some morphological features are difficult to appreciate with accuracy. The re-examination of this material has provided some differences from Altherr's original description - shorter body length (L = 1.36 vs. 1.55 mm), values of de Man indices " c " are lower, '' a' ', c', V are higher, size of vagina, saccate bodies described and illustrated in the original description are hardly visible, most likely due to flattening of the specimen and conservation. Meyl (1961) considered this species as species inquirenda. New observations reveal that several relevant traits (strong odontostyle with wide lumen, comparatively long pharyngeal expansion occupying ca. one-half of the total neck length, tail conical with rounded tip) are not compatible with those characterising the genus Enchodelus. Thus, this species is herein regarded as incertae sedis.