Examination of the type-specimens has revealed that Argas (Persicargas) radiatus Railliet, A. (P.) sanchezi Duges, and A. (P.) miniatus Koch are valid species and not synonyms of the fowl tick, A. (P.) persicus (Oken), as formerly believed. All these species parasitize poultry in the New World and radiatus and sanchezi are recorded also from various wild avian hosts. Keys, descriptions, illustrations, and data on hosts and distribution are given. The Old World species A. (P.) persicus appears to be rare in the New World; the only available collections are 7 from Maryland, 2 from Pennsylvania, and 1 each from Georgia, California, and Paraguay. A. (P.) radiatus is recorded from Florida, Iowa, Texas, and Tamaulipas, Mexico. A. (P.) sanchezi is recorded from Arizona, California, Nevada, New Mexico, Texas, Utah, and from Baja California, Durango, and Guanajuato in Mexico. A. (P.) miniatus is known from Panama, Trinidad, Colombia, and Brazil. Because of the confusion that has existed as to the identiy of Persicargas species in the New World, their distribution is still poorly known, and each undoubtedly occurs much more widely than is indicated by the collections that were available to the authors for study.