Trachelius Schrank, 1803 (ref. ID; 2013)
Class Kinetofragminophora: Subclass Gymnostomata: Order Haptorida: Family Tracheliidae (ref. ID; 2013)

[ref. ID; 2013]
Body shape variable, ovoid to spherical bearing short anterior, finger-like process or snout which points towards the dorsal surface. Posterior rounded never with tail region. An ciliated ridge lies along the ventral face of the snout at the base of which lies a circular oral aperture surrounded by the ridge as in Dileptus. The oral aperture is supported by trichites but the ridge is not lined with trichocysts. Ciliation is uniform and complete in longitudinal rows. Contractile vacuoles scattered throughout body. Macronucleus in one or two parts, usually elongate.
Quote; Colin R. Curds "British and other freshwater ciliated protozoa Part I Ciliophora: Kinetofragminophora" Cambridge University Press, 1982 (ref. ID; 2013)

Trachelius ovum Ehrenberg, 1831 (ref. ID; 1219, 1335, 1622, 1629, 2245, 3115) reported year? (ref. ID; 1618) or (Ehrenberg, 1831) Ehrenberg, 1835 (ref. ID; 4612) reported author and year? (ref. ID; 191, 3292)
Syn; Amphileptus ovum Dujardin, 1841 (ref. ID; 3115); Amphileptus rotundus Maskell, 1887 (ref. ID; 1622, 3115); Harmodirus ovum Perty, 1852 (ref. ID; 3115); Ophryocerca ovum Ehrenberg, 1831 (ref. ID; 4612); Trachelius leidyi Foulke, 1884 (ref. ID; 1622)
Description; More or less spheroidal with a distinct short proboscis; right side flattened, often somewhat concave; left side strongly convex; body ciliation uniform, rows of slightly longer cilia on the central face of the proboscis, the circular cytostome is located at the base of the proboscis; cytopharynx exhibiting long trichites; numerous contractile vacuoles; macronucleus sausage-shaped; a single micronucleus; endoplasm vacuolated, brown granules often concentrated in the posterior region. (ref. ID; 1219)
Spheroidal to ellipsoid; right side flattened and with a longitudinal groove; left side convex; proboscis about one-fourth to one-half the body length; cilia short and closely set; numerous contractile vacuoles; macronucleus short sausage-form, often divided into spherules; endoplasm penetrated by branching cytoplasmic skeins or bands and often with numerous small brown excretion granules; fresh water. (ref. ID; 1618)
Measurements; Length 200-400 um. (ref. ID; 1219, 1618)