The brief original description, without illustration, of Citharichthys fragilis was based on specimens collected in the central and northern Gulf of California, Mexico. We expand the description of the species, including its secondary sexual dimorphism, and compare it with C. gordae, a similar, relatively deep-water sanddab, mainly, although rarely, collected from the southern Gulf of California. We reject the recent placement of C. gordae in the synonymy of C. fragilis and conclude that both species are valid. They show an essentially allopatric distribution, C. fragilis being quasi-endemic and C. gordae endemic to Mexico. The distributional range of C. gnathus is widened from the Galapagos Islands to the Pacific coast of Colombia, and the Gulf of California is excluded from the geographical range of C. xanthostigma. A key to the species of Citharichthys from the eastern Pacific is provided.