46 



PROTOZOA 



Suborder 2. ACEPHALINA. 



No epimerite present, the body consisting of a single chamber; 

 spore spindle-shaped: about 10 genera and numerous species, which live 



principally in the body cavity 

 of the host and the organs con- 

 nected with it. 



MoNOCYSTis Stein. Body 

 ovoid or elongate, sometimes 

 with long cuticular filaments ; 

 individuals mostly solitary: 

 about 10 species. 



M. lumbrici (Henle) 

 {M. agilis Stein) (Fig. 67). 

 Length .2 mm.: in intestine, genital organs and coelom of the earth- 

 w^orm; common. 



M. clymenellae* Porter. In the body wall of Clymenella torquata. 



Pig. 67 — MonocysUs lumbrici (from Bronn). 



A, single individual; B, a spore; 



C, a cyst. 



Fig. 68 — Eimeria 

 stiedae (Doflein). An 

 infected intestinal epi- 

 thelium. 



Order 2. COCCIDIIDA. 



Sporosoa of spherical or ovoid shape without a free stage, which 

 live imbedded in the solid tissues of the host, usually as intracellular 

 parasites; reproduction by sporulation with an 

 alternation or generations: 5 families and 70 

 species. 



Eimeria Schneider (Coccidium Leuckart). 

 Cyst ovoid, each on sporulation forming 4 sporo- 

 blasts, each of which produces 2 spores: 13 

 species. 



E. stiedae (Lindemann) (E. cuniculi Rivolta) 

 (Fig. 68). In the liver and other organs of 



rabbits and other animals, also in the human liver; length of cyst 

 .04 mm. 



Order 3. H^MOSPORIDIIDA. 



Sporozoa parasitic in the blood of vertebrates, with or without a 

 change of hosts ; reproduction occurs by asexual spore-formation usually 

 in the body of some other animal where conjugation takes place fol- 

 lowed by pseudosexual spore-formation: about 4 genera. 



1. Plasmodium Marchiafava and Celli. An intra-corpuscular para- 

 site in mammalian blood corpuscles where it finally breaks up into about 

 12 asexual spores (merozoites) which are often grouped about a central 



♦ See "Two New Gregarinida," by J. F. Porter, Jour. Morph., Vol. 14, 1908. 



