We note that Lacrymaria is prolonged in front into a long, slender flexible "neck," with the mouth terminal. This swan-like conformation is "mimicked" by Dileptus and Lionotus, where the neck, like the prostomium of worms, is a mere extension of the front of the body above and beyond the mouth; all three swim with peculiar grace. Trachelius (Fig. 56) has a distinct cup-shaped sucker behind the mouth, and is remarkable, like Loxodes, for the branching disposition of its endosarc.
The pigment of this species has been examined and described by Lankester under the name of "blue stentorin" (Quart. Journ. Micr. Sci. xii. 1873).
For a full account of Caenomorpha, Metopus, and allied forms, see Levander, Beitr. z. Kenntn. einiger Ciliaten, Dissert. Helsingfors, 1894.
Torquatella typica, described by Lankester as possessing a continuous undulating membrane for its peristomial wreath, is identified by Bütschli as a Strombidium, possessing exceptionally large membranellae.
Outside the principal wreath is another of fine cilia ("paroral"), standing out at an angle.