Hydryphantes

Sabatino, Antonio Di, Gerecke, Reinhard, Gledhill, Terence & Smit, Harry, 2009, On the taxonomy of water mites (Acari: Hydrachnidia) described from the Palaearctic, part 2: Hydryphantoidea and Lebertioidea, Zootaxa 2266, pp. 1-34 : 14

Hydryphantes (s.str.) planus Thon, 1899

Hydryphantes (s.str.) bayeri nonundulatus K. Viets, 1919 , nov. syn.

Material examined: Hydryphantes bayeri nonundulatus holotype SMF 1959, Germany.

Discussion: Láska (1964) proposed H. nonundulatus as a separate species, but later he excluded it from his key to the Czech fauna ( Láska 1971). The proposal of Lundblad (1962) to consider this taxon a synonym of H. planus is supported by important facts: H. nonundulatus agrees with H. planus in the general shape of the frontal shield (the name-giving obtuse-angled, not undulating, shape of the anterior frontal shield margin is frequently found in populations of H. planus which are highly variable from this point of view). Also the shape of the gnathosomal rostrum (short and stout), chelicera (with a short claw) and palp agree in both taxa. Consequently, as proposed by Lundblad (1962), H. bayeri nonundulatus should be considered a junior synonym of H. planus .