LAUSR

Abstract A list of identified ptyctimous mites (Acari, Oribatida) from Mexico and Peru, including 12 species from seven genera and five families, is presented. Of these taxa, two species are new for science, and Protophthiracarus baloghi and Atropacarus (Hoplophorella) brachys are recorded in the Mexican fauna for the first time. Mesotritia cozumelensis Niedbała sp. nov. (Oribotritiidae) differs from congeners by a combination of the following characters: two pairs of parallel lateral carinae on the prodorsum; rostral setae situated between interlamellar and lamellar setae, but nearer to lamellar setae; very long exobothridial setae, five pairs of genital setae; two pairs of anal and three pairs of adanal setae; setae ad1 very long; equal distance between adanal setae. Arphthicarus simplex Niedbała sp. nov. (Steganacaridae) is distinguishable from congeners by the long line in extension of the sinus and by the distally curved rostral setae.