32 INTRODUCTION TO THE PROTOZOA 



Family CRYPTOSPORIDIIDAE 



Development on the surface of the host cell or within its 

 striated border and not in the cell proper. Oocysts and 

 schizonts with a knob-like attachment organ at some point 

 on their surface. Oocysts without sporocysts. Monoxenous. 

 Microgametes without flagella. 



Crxptospu)-idii(7n 



Family AGGREGATIDAE 



Development in host cell proper. Oocysts typically with 

 many sporocysts. Heteroxenous. Schizogony in one host, 

 sporogony in another. 



Merocystis 



Family LANKESTERELLIDAE 



Development in host cell proper. Oocysts without sporo- 

 cysts, but with 8 or more sporozoites. Heteroxenous, with 

 schizogony, gametogony and sporogony in a vertebrate host. 

 Sporozoites in blood cells, transferred without developing 

 by an invertebrate (mite or leech). Microgametes with 2 

 flagella, so far as is known. 



Lankesterello 

 Schellackia 



Suborder HAEMOSPORORINA 



Macrogamete and microgametocyte develop independently. Syzygy 

 absent. Microgametocyte produces moderate number of micro- 

 gametes. Zygote motile (ookinete). Sporozoites naked. Heter- 

 oxenous. Schizogony in vertebrate host, sporogony in inverte- 

 brate. Pigment (hematin) formed from host cell hemoglobin. 



Family PLASMODIIDAE 



With the characters of the suborder. 



Haemoproteus Leucocytozoon 



Hepatocystis Plasmodium 



Class PIROPLASMASIDA 



Small, piriform, round, amoeboid or rod-shaped parasites of vertebrate erythro- 

 cytes and also in some cases of leucocytes or histiocytes. Pigment (hematin) not 



