592 PROTOZOOLOGY 



tubules of Hydroporus palustris; oocysts ovoid, 20-25// long, with 

 16 sporozoites which measure 17m by 3m (Vincent, 1927). 



Genus Chagasella Machado. Oocyst with 3 spores, each with 4 

 or 6 (or more) sporozoites; in hemipterous insects. 



C. hartmanni (Chagas). In the gut of Dysdercus ruficollis; oocysts 

 with 3 spores about 45m in diameter; spore with 4 sporozoites, about 

 35m by 15m (Machado, 1911). 



Genus Ithania Ludwig. Microgametocyte produces four micro- 

 gametes; oocyst with one to four spores, each with nine to 33 sporo- 

 zoites. One species (Ludwig, 1947). 



I. weririchi L. In the epithelial cells of the gastric caeca and mid- 

 gut of the larvae of the crane-fly, Tipula abdominalis; oocysts 34- 

 63m by 22-50m- 



Family 2 Haemogregarinidae Leger 



With 2 hosts: vertebrates (circulatory system) and invertebrates 

 (digestive system) . 



Genus Haemogregarina Danilewsky. Schizogony takes place in 

 blood cells of vertebrates; when gametocytes are taken into gut of 

 leech or other blood-sucking invertebrates, sexual reproduction takes 

 place; microgametocyte develops 2 or 4 microgametes; sporozoites 

 formed without production of spores. 



H. stepanowi D. (Fig. 255). Schizogony in Emys orbicularis and 

 sexual reproduction in Placobdella catenigera; sporozoites introduced 

 into blood of the chelonian host by leech (a), and enter erythrocytes 

 in which they grow (d-g) ; schizogony in bone-marrow, each schizont 

 producing 12-24 merozoites (h); schizogony repeated (i); some 

 merozoites produce only 6 merozoites (j, k) which become gameto- 

 cytes (l-o); gametogony occurs in leech; 4 microgametes formed 

 from each microgametocyte and become associated with macro- 

 gametocytes in gut of leech (p-r) ; zygote (s) divides three times, and 

 develops into 8 sporozoites (t-w). 



Haemogregarines are found commonly in various birds (Aragao, 

 1911), reptiles, amphibians (Fig. 254, g, h) (Roudabush and Coat- 

 ney, 1937) and fishes (Fig. 254, i-m). 



Genus Hepatozoon Miller. Schizogony in the cells of liver, spleen, 

 and other organs of vertebrates; merozoites enter erythrocytes or 

 leucocytes and develop into gametocytes; in blood-sucking arthro- 

 pods (ticks, mites), micro- and macro-gametes develop and unite in 

 pairs; zygotes become oocysts which increase in size and produce 

 sporoblasts, spores, and sporozoites. 



H. muris (Balfour) (Fig. 254, n). In various species of rat; several 



