202 SPOROZOA, 



merozoites. When the crab is eaten by a cuttlefish, the 

 merozoites penetrate the gut-wall and develop into micro- 

 and macrogametocytes, and further into gametes. Anisogamy 

 results in zygote formation, and the oocysts are passed out 

 and ingested by another crab. 



138. Aggregata sp. 



•fAggregata sp., Setna & Bhatia, 1934, pp. 42-3, fig. 23. 



Schizonts spherical or oval, and are enclosed in a cyst. 

 Each cyst has six or seven pear-shaped apertures through 

 which merozoites escape. The merozoites are curved spindle- 

 shaped bodies, with a broad central portion and pointed ends ; 

 the nucleus consists of deeply staining granules and occupies 

 one end. The merozoites move with sudden jerky or springy 

 movements, and the nuclear end is usually anterior in these 

 movements. 



Dimensions. — Schizonts 193-246 /u. in diameter; merozoites 

 ll-16ju. in length. 



Habitat. — Intestine of the prawn, Parapeneopsis sculptilis 

 (Heller) : Bombay, Bombay. 



Incert^ sedis. 

 Genus TOXOPLASMA Nicolle & Manceaux, 1909. 



Toxoplasma, Nicolle & Manceaux, 1909 a, pp. 369-72 ; 1909 6, 

 pp. 97-103; Splendore, 1909, pp. 462-5; Carini, 1909, pp. 465-9 ; 

 1911 a, p. 518 ; Ugo Mello, 1910, pp. 359-63; Yakimoff & Kohl- 

 Yakimoff, 1911a, pp. 617-18; 1912, pp. 1-14; Bourret, 1911, 

 p. 373 ; Sangiorgi, 1913, p. 323 ; 1914, p. 83 ; MaruUaz, 1913, 

 pp. 323-6 ; Laveran& MaruUaz, 1914, pp. 21-5 ; Castellani, 1914, 

 p. 113 ; Castellani & Chalmers, 1919, pp. 488-90 ; NoUer, 1920, 

 pp. 907-18; Hegner & Taliaferro, 1924, pp. 293, 300-2; Brug, 

 den Heyer, & Haga, 1925, pp. 232-8. 



Babesia (Toxoplasma), Calkins, 1926, p. 445. 



Toxoplasma, Wenyon, 1926, pp. 1041-50; Knowles, 1928, pp. 463-5; 

 Reichenow, 1929, p. 965 ; NoUer, 1931, pp. 804-7. 



Organism small, elongated, shghtly curved, with a central 

 nucleus. Found in the host-cells either singly or in groups 

 resulting from repeated binary fission. When occurring 

 singly they often he against the nucleus of the host-cell and 

 indent it, thus bearing some resemblance to the leucocytic 

 Hsemogregarines. Parasites of body fluids, leucocytes, and 

 cells of the spleen, liver, kidneys, lungs, etc., of various 

 Vertebrates. 



Species have been described from man, monkeys, dogs, 

 gondis, rabbits, rats, guinea-pigs, moles, birds, and snakes. 



Remarks. — It is not possible to determine the correct 

 position of Toxoplasma in the scheme of classification till more 



