Enchytraeids are an important component of Arctic ecosystems both as decomposers and part of the foodchain. Compared to other regions of the High Arctic, the enchytraeid fauna of Spitsbergen and some other islands of the Svalbard archipelago have been explored rather well but we still lack information from many areas and specific habitats. In August 2018, potworms (Annelida: Clitellata: Enchytraeidae) were sampled on the lower portion of a talus slope and in the flat area between this slope and the beach of Skansbukta, a bay of the Isfjord(en) on the western coast of Spitsbergen. Objectives were to compare assemblage composition and densities of close-by sites differing in their environmental characteristics, to provide faunistic data for a little explored area within Spitsbergen, and to clarify the true identity of Marionina argentea s.l., which had been found here previously. Six taxa on species level were recorded, including a Mesenchytraeus species of uncertain identity. Using morphological and molecular characters, Marionina argentea s.l. was shown to be M. mimula, a species described rather recently from Ireland and Sweden and hitherto not known from the Svalbard archipelago. This species dominated the moist flat area, substantially contributing to the higher enchytraeid density of ca 10 000 individuals/m2 compared to less than 3 000 ind./m2 on the lower slope. In the flat area ca 70 % of enchytraeids were present in the uppermost 3 cm layer consisting of mainly live mosses, whereas on the lower slope the distribution of individuals between the 0–3 and 3−6 cm layers was very balanced but no individuals occurred in greater depth, though there was no apparent change in the character of the moss-derived organic soil with depth.