The mature ooxysts of six new species of Caryospora are described from the faeces of Brazilian snakes. They are differentiated from other species previously recorded from reptiles, largely on the size and shape of the oocyst and sporocyst, structure of the oocyst wall, and presence or absence of a polar body. C. paraensis n. sp., and C. carajasensis n. sp., are from the "false coral", Oxyrhopus petola digitalis; C. pseustesi n. sp., from the "egg-eater", Pseustes sulphureus sulphureus; C. epicratesi n. sp., from the "red boa", Epicrates cenchria cenchria; and C. micruri n. sp., and C. constancieae n. sp., from the "coral snake", Micrurus spixii spixii. A re-description is given of C. jararacae Carini, 1939, from the "jararaca" Bothrops atrox, embodying some additional morphological features.
Apicomplexa; Eimeriidae; Caryospora; Caryospora carajasensis n. sp.; Caryospora paraensis n. sp.; Caryospora pseustesi n. sp.; Caryospora epicratesi n. sp.; Caryospora micruri n. sp.; Caryospora constanciae n. sp; Caryospora jararacae; Oxyrhopus petola digitalis; Pseustes sulphureus sulphureus; Epicurates cenchria cenchria; Micrurus spixii spixii; Bothrops atrox; coccidia; oocysts; snakes; Serpentes; Brazil