Xystonotus Wolcott, 1900

Pešić, Vladimir, Cook, David, Gerecke, Reinhard & Smit, Harry, 2013, The water mite family Mideopsidae (Acari: Hydrachnidia): a contribution to the diversity in the Afrotropical region and taxonomic changes above species level, Zootaxa 3720 (1), pp. 1-75 : 9

Genus Xystonotus Wolcott, 1900 , nov. stat.

Type species: Xystonotus aspera Wolcott, 1900

Diagnosis: Dorsal shield with a pronounced V- or U-shaped ridge; posterior suture lines of fourth coxae well developed; a well developed ridge extending anterolaterally from suture line between Cx-III and Cx-IV; Cxgl- 2 located in a line with or only slightly anterior to anterior end of gonopore, the gland portion occasionally absent; openings for insertion of IV-L without condyles; three pairs of Ac; swimming setae typically absent, but present in one South African species; palp not uncate and with an enlarged, forward-directed tubercle bearing two small setae; except for genital field no sexual dimorphism of idiosoma, legs or palp.

Remarks: With the discovery of a species from Madagascar (to be described later in this paper) with even closer affinities to Xystonotus than Mideopsis (Mixomideopsis) sandola Cook, 2001 from South Africa, it was decided that these two species should be in a subgenus assigned to the genus Xystonotus . We have no explanation that accounts for this disjunct distribution.

Distribution: Disjunct. The nominate subgenus is Holarctic; the subgenus Mixomideopsis known only from southern Africa.