-Webb, S. A., and R. R. Millel: Zoogoneticus tequila, a new goodeid Jish (Cyprinodontiformes) from the Ameca drainage of Mexico, and a rediagnosis of the genus. Occ. Pap. Mus. Zool. Univ. Michigan 725:l-23, 5figs. Zoogoneticus tequila n.sp. is described from the Rio Teuchitlfin, an upper tributary to the Ameca drainage, .Jalisco, Mexico. The new species can be distinguished from its congener, Z. quitzoensis, by adult males having a broad, red-orange band of pigment subterminally in the caudal fin, with melanization in the caudal fin restricted to a proximal, paddle-shaped region. The dorsal and anal fins of adult males possess narrow terminal bands of light yellow color. The laterocaudal pigment bars in both sexes are much less intense and fade at a younger age. The genus Zoogoneticus is diagnosed by the presence of a membrane attaching the sixth pelvic ray to the ventral midline of the body, pigment patches on the posteroventral part of the body, two basicaudal spots that may coalesce, dorsal and anal fins of adult males with narrow terminal bands of red-orange or yellow pigment, with melanization basally, and trophotaeniae with 9 to 14 termini.