The 2 new spp. are described from oocysts in the feces of mammals from Grand Canyon National Park, Arizona. The oocysts of K. per-glexens from Peromyscus maniculatus measure 39.9 by 47.9 [mu] and contain 12 spherical sporocysts 13.3 [mu] in diameter. The oocysts of K. variabilis from the Corynorhinus rafinesquii aver-age 30.4 by 39.3 [mu] and contain 4 to 13 (average 8.5) spherical sporocysts. An unsuccessful attempt was made to infect baby white rats with K. variabilis.