THE SPOROZOA 169 



Order i . MYXOSPORIDIIDA. Neosporidia of amoeboid or spherical shape ; multi- 

 nuclear. The initial free stage is passed in the cavities of the organs, or in the 

 tissues of the host. In sporulation a definite or an indefinite number of sporo- 

 blasts is formed, each of which gives rise to one or several spores ; the latter are 

 provided with one or several polar capsules, which contain coiled threads like a 

 nematocyst. Each spore gives rise to one amoeboid sporozoite. 



Suborder i. PIL3SNOCYSTINA. Spores with polar capsules distinctly visible when 

 fresh. 



Family i. Myxidiidae. Myxosporidiida' forming two or more spores at the same 

 time. Spores variable in form inclosing two polar capsules. Genera : 

 Spharospora Thelohan ('92) ; Leptotheca The'l. ('95) ; CeratomyxaT\\&\. ('92) ; 

 Myxidium Blitschli ('82) ; Sphceromyxa Thel. ('92) ; Cystodiscns Lutz ('89) : 

 Myxosoma Thel. ('92). 



Family 2. Chloromyxidse . The spore has four polar capsules. Genera: Chloro- 

 myxum Mingazzini ('90). 



Family 3. Myxobolidae. Adult stages very rare, ordinarily found encysted in the 

 tissues ; usually polysporous. The spores have one or two polar capsules. 

 Genera: Myxobolus Biitschli ('82) ; Hemieguya Thel. ('92). 



Suborder 2. MICROSPORIDIINA. Myxosporidiida in which the spores have but one 

 polar capsule, which is invisible in the fresh state without the use of reagents. 



Family i. Nosematidce. With a bivalve spore. Genera: Nosema Na'geli ('57) 

 (Glugea Thelohan, '92) ; Plistophora Gurley ('93) ; Thelohania Henneguy l ('9 2 )- 



Order 2. SARCOSPORIDIIDA. Sporozoa in which the initial stage is passed in 

 muscle-cells of vertebrates. The form is usually elongate, tubular or oval, or 

 sometimes spherical. It forms cysts with a double membrane, in which are 

 formed kidney-shaped or falciform sporozoites, or else spores (?), provided with 

 a polar capsule and projectile thread. Genera: Sarcocystis Lankester ('82). 



SPOROZOA INCERT^E SEDIS 



Amcebosporidia. Sporozoa possessing an amoeboid body, and reproducing either by 

 division or by spore-formation after conjugation. Gene'ra : Ophryocyslis A. Schn. 



Serumsporidia. Sporozoa which reproduce by division (?) or by spore-formation, 

 the sporozoites being minute oval or spherical bodies They are found in the 

 cavities or ccelomic fluids of Invertebrates and Vertebrates. Genera: Serum- 

 sporiditiin L. Pfeiffer ('95) ; Blanchardina Labbe ('99) ; Lymphosporidium 

 Calkins (1900). 



SPECIAL BIBLIOGRAPHY V 



Gurley, R. R. The Myxosporidia, or Psorosperms of Fishes, and the Epidemics pro- 



duced by them. Bull. U. S. Fish Comm. XL, 1893. 

 Labbe, A. Recherches zoologiques, cytologiques et biologiques sur les Coccidies. 



Arch. d. zool. exper. et gen. (3) IV., pp. 517-654, 1896. 

 LabbS, A. Sporozoa. In Das Tierreich, Berlin, 1899. 



Leg6r, L. Recherches sur les Gregarines. Tablettes zoologiqrtes , III., pp. 1-182, 1892. 

 Leuckart R. Die Parasiten des Menschen. Leipzig, 1879.' 

 Ross. D. On Some Peculiar Pigmented Cells found in Two Mosquitoes fed on Mala- 



rial Blood. Brit. Med. and Surg. Jour., 1897, pp. 1786-1788. 

 Schneider, A. Sur les psorospermies oviformes ou Coccidies, especes nouvelles ou 



peu connues. Arch. d. zool. exper. et gen. (i) IX., pp. 387-404, 1881. 

 Siedlecki. M. Etude cytologique et cycle evolutif de la coccidie de la seiche. Ann. 



d. Vlnst. Pasteur, XII., 



