Ciliates of the genus Gruberia are poorly studied. Consequently, most species lack detailed morphological descriptions, and all gene sequences in GenBank are not classified at the species level. In this study, a detailed morphological description of a population of G. lanceolata from Brazil is presented, based on live and protargol-stained organisms. We also present the 18S rRNA gene sequence and the phylogenetic position of this species. The primary characteristics of G. lanceolata from the Maricá Lagoon are as follows: an elongate fusiform body 280–870 × 40–160 μm in size; rosy cortical granules; a peristome occupying approximately 1/3–1/2 of body length; an adoral zone comprising 115–330 membranelles; a paroral membrane in 35–50 fragments; and a moniliform macronucleus with 11–16 nodules. Based on our observations and data from pertinent literature, we suggest G. beninensis to be a junior synonym of G. lanceolata. © 2018 International Society of Protistologists