Ten morphological characters and two electrophoretic characters were studied in nearly 200 specimens of johnny and tessellated darters from the Ottawa area. The data were analyzed using a simple character index and principal component analysis. The frequency distribution of the character index was trimodal, and specimens could be resolved into three groups: those typical of johnny and tessellated darters, and a group of intermediates. The two extreme groups were interpreted as representing two valid species, Etheostoma nigrum Rafinesque and Etheostoma olmstedi Storer, and part of the intermediate group was inferred to consist of interspecific hybrids. Hybrids were estimated to constitute less than 7.6%. There was no clear evidence of backcrossing. Most specimens could be clearly identified with one or the other of the two species. A key is provided.