So far I have only found Loxocephalus plagius in the Simmelried. However, as it is a very common ciliate, I assume that it also occurs in my other sites with a layer of mud and rotting plant parts.

Loxocephalus plagius is very easy to confuse with Dexiotricha granulosa, as both species are about the same size. In Dexiotricha granulosa, however, the granules in the cytoplasm are ring-shaped and the cilia (inclusive the caudal cilium) are rigid and straight. In addition, the mouth opening of Dexiotricha granulosa is smaller and the left side is C-shaped. In Loxocephalus plagius the mouth opening is elongated, almost crescent-shaped and on the left edge there is a characteristic angle of about 120 °, as also drawn by Kahl (s. drawing above and figs. 1 c and 4 c).

In my population of Loxocephalus plagius I could find distinct, spindle-shaped extrusomes, which are 2.2–3.3 µm long and are arranged beneath the pellicle (s. figs. 2 a, 3 a and 5). These extrusomes are not mentioned or drawn by Kahl in his very short description.