Paruroleptus Kahl, 1932 (ref. ID; 2014)
Class Polyhymenophora: Subclass Spirotricha: Order Hypotrichida: Suborder Stichotrichina: Family Holostichidae (ref. ID; 2014)

[ref. ID; 2014]
Elongate body tapers posteriorly into a long tail that is turned slightly towards the animal's right and bears caudal cirri. 2 rows of marginal cirri and 2 midventral rows, extending into the frontal region. In addition, there are 3 strong anterior frontal cirri, and sometimes a buccal cirrus. Transverse cirri present. AZM occupies about third of anterior region. 2 macronuclei centrally placed, each with an adjacent micronucleus. Several species have been described. Borror (1972) considers this genus to belong to Uroleptus, while Jankowski (1979) designates the type species as P. lacteus Kahl, 1932.
Quote; Colin R. Curds, Michael A. Gates and David McL. Roberts "British and other freshwater ciliated protozoa Part II Ciliophora: Oligohymenophora and Polyhymenophora" Cambridge University Press, 1983 (ref. ID; 2014)

Paruroleptus notabilis Foissner, 1982 (ref. ID; 662 original paper, 2128)
Description; Description of Antarctic population; Slenderly ellipsoid to slightly sigmoidal and/or pisciform, i.e. rather distinctly narrowed posteriorly. Very flexible and dorsoventrally inconspicuously to distinctly (up to 2:1) flattened. Macronuclear nodules globular to ellipsoidal, arranged in 2-3 loose rows mainly in left half of cell. Micronuclei conspicuous because compact and large, in vivo up to 7 x 3 um, usually 1 each near end of macronuclear chain, stain weakly with protargol. Contractile vacuole slightly above mid-body. Cortex flexible, contain tiny (diameter < 0.5 um), colourless granules mainly around cirral bases and dorsal bristles. Cytoplasm colourless, without crystalline inclusions, posterior portion usually filled with 2-5 um sized, colourless fat globules. Glides and swims rather slowly. Transverse and caudal cirri distinct; 1 isolated cirrus at end of midventral row (n = 10). Oral apparatus inconspicuous, adoral zone of membranelles occupies only about 24% of body length, bases of largest membranelles 6 um wide in vivo. Buccal cavity narrow and flat, almost entirely covered by very hyaline lip. Paroral and endoral membrane slightly curved, intersect optically, paroral conspicuously short, i.e. about half the length of endoral. Pharyngeal fibres conspicuous but not surrounded by special structures. (ref. ID; 2128)
Notes; As Blatterer and Foissner (1988) mentioned, P. notabilis is a difficult species. As yet, four populations (Antarctic, Australian, German, Austrian population) have been studied. All differ in some important details. The Antarctic specimens resemble the German population best, especially in the inconspicuous cortical granules. However, they have slightly more adoral membranelles, a distinctly higher number of marginal cirri, and fewer macronuclear nodules and dorsal kineties. Furthermore, the macronuclear nodules are more regularly arranged than in the other populations in which they are irregularly distributed. Similar differences are found also between the other populations. Thus, it seems reasonable to consider all populations as nonspecific, at least at the present state of knowledge. (ref. ID; 2128)
Measurements; In vivo 90-140 x 15-20 um. (ref. ID; 2128)