Xystonotus Wolcott, 1900

Genus Xystonotus Wolcott, 1900 View in CoL , 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.