Genus Zapteryx Jordan & Gilbert, 1880

Type species. Platyrhina exasperata Jordan & Gilbert, 1880 (by original designation).

Description. Nostrils small, internasal distance subequal to nostril length; posterior aperture narrow, not greatly oblique. Anterior nasal flaps weakly bilobed, expanded laterally but not fused to form a nasal curtain, long based, inserted on snout lateral and well mesial to innermost corner of posterior aperture (insertions of flaps well separated, much more than anterior aperture width; anterior aperture small, suboval, medial edge partly formed by long and broad outer lobe-like extension of anterior nasal flap; posterior lobe of anterior nasal flap tall with an almost horizontal to weakly concave margin, partly overlapping posterior aperture; posterior margin of anterior aperture bordered by relatively broad posterolateral nasal flap, extending medially beneath anterior nasal flap; posterior nasal flap very well developed, expanded beyond anterior nasal-flap margin and base much longer than anterior aperture width. Lower jaw slightly convex; skin margin forming upper lip very concave; several lateral grooves at mouth angle; oral groove well developed laterally, forming corrugated ridges on chin.

Species: Z. brevirostris (Müller & Henle, 1841), Z. exasperata (Jordan & Gilbert, 1880), Z. xyster Jordan & Evermann, 1896.