[[ Hemigrammus Gill]]
The genus Hemigrammus Gill, 1858 is one of the most diverse in the Characidae, presently with 45 species recognized as valid and widely distributed in Neotropical cis-andean river basins (Lima et al., 2003; Bertaco & Carvalho, 2005, Zarske et al. 2006). Currently allocated as incertae sedis in Characidae (see Lima et al., 2003), Hemigrammus has not been investigated since the monograph of Géry (1977). Géry, based on the extensive revision of the genus presented by Marion Durbin Ellis in Eigenmann (1918), defined Hemigrammus by the presence of premaxillary teeth in two rows, inner row with five or more teeth, scale sheath covering the caudal-fin lobes, and an incomplete lateral line. According to Bertaco & Carvalho (2005), the notable anatomical diversity within Hemigrammus and the high number of species recognized are likely to be the major reasons behind the lack of phylogenetic analyses of its species, as well as of the genus among characids. Examination of several lots from Museo de Ciencias Naturales de Guanare, Venezuela, revealed a new and sexually dimorphic species of Hemigrammus, which is described herein.