ISOSPOEA. 171 



published. The form is said to differ from /. dirumpens 

 Hoare in that development inside the oocyst takes place 

 outside the body of the host. The disporocystid condition of 

 the oocyst was evidenced after being kept in 1 per cent, chromic 

 acid for three days. It also differed from /. naiee Fantham 

 in that there was no oocystic residuum. 



Habitat. — ^In the fsecal matter oiNaja naja (Linn.) : Bengal, 

 Calcutta. 



101. Isospora rivolta (Grassi). (Fig. 78.) 



Goccidium rivolta, Grassi, 1879, p. 135, pi. xxxiii, figs. 41-4 ; 1881 a, 



p. 632. 

 Goccidium bigeniinuni, Labbe, 1899, p. 67. 



Isospora rivolta. Brown & Stammers, 1922, p. 1165; Wenyon, 

 1923 a, p. 260, figs. 12-15 ; 1926, pp. 808, 813, figs. 342, 345, 

 346, 350. 

 ■fisospora sp., ("type A "), Knowles, 1928, p. 354, fig. 81, 2. 

 Isospora rivolta, Reichenow, 1929, pp. 956-7, fig. 921 b ; Kudo, 1931, 



p. 274, fig. 114e. 

 ■fisospora rivolta, Knowles & Das-Gupta, 1931, pp. 175-6, pi. ix. 

 ■\Isospora sp. ("type A"), Knowles & Das-Gupta, 1934, pp. 387-90, 



pi. vii, figs. 5, 6. 

 "fisospora rivolta, Aiyar, 1937, p. 402. 



Oocysts ovoid, with a double contour. In each are developed 

 two sporocysts, and a small residual body may be present. 

 The sporocysts are elongate bodies with rounded ends. 



Fig. 78. — Mature oocyst oi Isospora rivolta (Grassi). 

 (After Reichenow.) 



Each sporocyst contains four sporozoites and a large residual 

 body filled with globules of a refractile material. The infection 

 is usually confined to the epithehal layer, but the form may 

 also reproduce in subepithehal tissues of the alimentary canal 

 of the host and produce male and female gametocytes. 



Dimensions. — Oocysts 20-25 /x in length by 15-22^ in 

 breadth ; sporocysts 16 ju, by 10|Li. 



