S. Mahunka szerk.: Folia Entomologica Hungarica 55. (Budapest, 1994)

Liothorax muscorum sp. n. In general appearance extremely similar to Liothorax plagiatus (Linnaeus, 1767). Body convex, elongate oval, moderately broadening posteriorly; slightly shining, pitchblack in colour, antennae and palpi fuliginous, tarsi pitch-black to dark brown. Head transverse quadrangular, convex, surface strongly, somewhat irregularly punctuated, particularly near margins. Anterior clypeal margin slightly emarginate, anterior angles broadly rounded. Frontal tubercles absent. Genae obtusely angulate. Pronotum transverse quadrangular, strongly convex, arcuately narrowing anteriorly, posterior angles obtusely rounded. Lateral and basal margin distinctly bordered but basal border broadly interrupted at middle. Surface moderately, somewhat irregularly, lateral sides densely punctuated. Elytra uniformly black in colour, surface finely microreticulated, slightly shining or almost dull. Striae distinctly punctuated, elytral intervals barely convex, finely but distinctly punctuated. Scutellum subpentagonal. Upper terminal spur of hind tibiae a little shorter than first tarsal segment. Apical setae of middle and hind tibiae short and equal in length. Length: 4-5 mm. Holotype (sex not studied): Hung., Borsod-Abaúj-Zemplén m., Aggtelek, Vörös-tó, 350 m, Typhetum angustifoliae-latifoliae, iszapból [from mud], 1989. V. 19., leg.: Ádám L. The type is deposited in the Department of Zoology of the Hungarian Natural History Museum, Budapest. Bionomy: Liothorax muscorum sp. n. is a typical species for water-dependent treeless habitats. It occurs in moist soil, in drying-out marshes, puddles, in meadows, etc., feeds on small mosses, on algae, on decaying plant substances rotting in mud, etc. The two species, Liothorax muscorum and Liothorax plagiatus very closely resemble each other; the external features (not rugosely punctuated clypeus, distinctly punctuated elytral striae, finely punctuated elytral intervals) by which Liothorax muscorum is distinguished are not very evident. A careful comparison is required for the determination of these species. This species should not be named as Scarabaeus niger Panzer, 1797 with which most of the authors have attached it. The head of the species described by Panzer (1797) has three tubercles (in the original description Panzer says: "...tuberculis tribus obsoletis", as it is shown in Fig. 37: 1 in his work). In addition the beetle was found in dung ("Habitat in stercore..."), which suggests that the species described by Panzer is identical with Scarabaeus bimaculatus Fabricius, 1787. (This name is a junior primary homonym of Scarabaeus bimaculatus Laxmann, 1770. The name Scarabaeus niger Panzer, 1797 itself also is preoccupied: it is a junior primary homonym of Scarabaeus niger Giorna, 1791. These should be replaced by the name Aphodius variáns Duftschmid, 1805.) There are no available synonyms for the species Scarabaeus niger auct. (the name Aphodius limnophilus Harold, 1871 was published originally as a junior objective synonym of Scarabaeus niger Panzer, 1797, therefore, it is unavailable), so I have described it as a new species.