Belongs within: Hygrobatoidea.
Lethaxona is a genus of interstitial mites known from southern Eurasia, eastern Africa and western North America. Lethaxona (Eolethaxona) oregonensis is distinguished from the species in the subgenus Lethaxona sensu stricto by the absence of the sexual dimorphism in palp and leg morphology found in the latter.
Characters (from Valdecasas 2010): Body shape broadly oval; central dorsal plate punctate; first pair of dorsolateral platelets not fused; glandularia present next to insertions of fourth legs; three pairs of acetabula present, arranged in a triangle; male gonopore anterior to acetabula.
Lethaxona Viets 1932S86
| i. s.: L. fonticola Walter & Bader 1952S86
|--L. (Lethaxona)S86
| |--L. (L.) cavifrons Szalay 1943S86
| |--L. (L.) flexipalpis Cook 1981S86
| |--L. (L.) gallica Angelier 1949S86
| |--L. (L.) heteropalpis Uchida & Imamura 1953S86
| |--L. (L.) hyogoensis Imamura 1957S86
| |--L. (L.) kutapalpis Cook 1967S86
| |--L. (L.) mikawensis Imamura 1957S86
| |--L. (L.) miurai Imamura 1957S86
| |--L. (L.) morimotoi Imamura 1977S86
| |--L. (L.) panduvarna Cook 1967S86
| `--L. (L.) pygmaea Viets 1932S86
`--L. (Eolethaxona Cook 1963)S86
`--L. (E.) oregonensis Cook 1963S86
*Type species of generic name indicated
References
Cook, D. R. 1963. Studies on the phreaticolous water mites of North America: new or unreported genera of Axonopsidae. American Midland Naturalist 70 (1): 110–125.
[S86] Schwoerbel, J. 1986. Acari: “Hydrachnellae”. In: Botosaneanu, L. (ed.) Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna inhabiting Subterranean Waters (including the Marine Interstitial) pp. 652–696. E. J. Brill/Dr W. Backhuys: Leiden.
Valdecasas, A. G. 2010. A new genus and species of the family Lethaxonidae (Acari, Parasitengona, Hydrachnidia) from the island of Coiba (Panama). Graellsia 66 (1): 21–28.