Class III. SPOROZOA, Leuckart, 1879 128 Sub-class. TELOSPORIDIA, Schaudinn 129 Order. _Gregarinida_, Aimé Schneider emend. Doflein 129 Order. _Coccidiidea_ 135 Genus. _Eimeria_, Aimé Schneider, 1875 142 _Eimeria avium_, Silvestrini and Rivolta 142 _Eimeria stiedæ_, Lindemann, 1865 145 (_a_) Human Hepatic Coccidiosis 148 (_b_) Human Intestinal Coccidiosis 148 (_c_) Doubtful Cases 149 Genus. _Isospora_, Aimé Schneider, 1881 149 _Isospora bigemina_, Stiles, 1891 149 Doubtful Species 150 Order. _Hæmosporidia_, Danilewsky emend. Schaudinn 151 The Malarial Parasites of Man 155 Development of the Malarial Parasites of Man 159 The Species of the Malarial Parasites of Man 164 _Plasmodium vivax_, Grassi and Feletti, 1890 164 _Plasmodium malariæ_, Laveran 166 _Laverania malariæ_, Grassi and Feletti, 1890 (= _Plasmodium falciparum_, Welch, 1897) 167 _Plasmodium relictum_, Sergent, 1907 (in birds) 170 Cultivation of Malarial Parasites 170 Differential Characters of the Human Malarial Parasites 171 Family. _Piroplasmidæ_, França, 1909 172 Genus. _Babesia_, Starcovici, 1893 174 Genus. _Theileria_, Bettencourt, França and Borges, 1907 178 _Theileria parva_, Theiler, 1903 178 _Theileria mutans_, Theiler, 1907 180 Genus. _Anaplasma_, Theiler, 1910 180 Genus. _Paraplasm_a, Seidelin, 1911 180 Sub-class. NEOSPORIDIA, Schaudinn 181 Order. _Myxosporidia_, Bütschli 181 Order. _Microsporidia_, Balbiani 184 Order. _Actinomyxidia_, Stolč. 187 Order. _Sarcosporidia_, Balbiani 187 _Sarcosporidia_ observed in Man 193 Order. _Haplosporidi_a, Caullery and Mesnil, 1899 194 _Rhinosporidium kinealyi_, Minchin and Fantham, 1905 195