Eimeria auritanensis n. sp. and E. gambai Carini, 1938 (Apicomplexa: Eimeriidae) from the opossum Didelphis aurita Wied-Newied, 1826 (Marsupialia: Didelphidae) from southeastern Brazil.

Two eimerid species are described from the opossum Didelphis aurita from southeastern Brazil. Eimeria auritanensis n. sp. sporulated oocysts spherical to subspherical (31.55 +/- 1.56 by 29.55 +/- 1.40 microm), shape index 1.07; oocyst wall double layered 2.10 +/- 0.27 microm thick, outer yellowish and strongly ornamented having a prominently mammillated surphace; inner layer smooth and brownish. There is no micropyle or oocyst residuum, but one or two polar granules are present. Sporocysts ovoid (13.20 +/- 1.64 by 10.41 +/- 1.10microm) with a faint Stieda's body and residuum composed of granules and spherules. Eimeria gambai Carini, 1938 sporulated oocysts ovoid to subspherical (26.54 +/- 1.7 by 24.82 +/- 1.85 microm), shape index 1.07; oocyst wall double layered 2.10 +/- 0.27 microm thick, outer colorless to pale yellow entirely pitted, while inner layer smooth dark yellow to pale brow. Micropyle and residual bodies absent, polar granules present. Sporocysts ovoid 12.49 +/- 1.75 by 9.32 +/- 1.01 microm. Stieda body present and round. Sporocysts residuum composed of many granules and spherules.