A survey of Sminthurides Börner, 1900 with specimens from the Americas was performed and two new species from Mexico are described and illustrated (drawings and SEM photographs), including a detailed study of body chaetotaxy. Sminthurides cihuatlensis sp. nov. is part of the Aquaticus group by the presence of ciliate seta B1 on Ant. II; it has a narrow mucro and lives in soil from the slopes of Iztaccíhuatl volcano. Sminthurides fridakahloae sp. nov. belongs to the Penicillifer group by the presence of Tra-2 on the Ant. II; it has a broad, trilamellate mucro, dens with plurichaetosis, and lives on surface freshwater from Colima and Morelos states. In addition, a key for the species is provided.
Keywords: Symphypleona; Taxonomy; morphology; sexual dimorphism.