Systematics and variation of a new cyprinodontid fish, Cyprinodon fontinalis, from Chihuahua, Mexico

" Cyprinodon fontinalis, new species, is described from a clus-ter of springs in the endorheic Guzman Basin of northwestern Mexico. It differs from other pupfishes in head form, coloration, and meristic charac-ters. Populations in five springs are variously distinct in coloration and meristic characters "