PYTHONELLA. 199 



Subfamily BARROUSSIIN^ (Wenyon, 1926). 



Oocysts contain many sporocysts, each containing one or 

 four sporozoites. 



Genus PYTHONELLA Ray & Das-Gupta, 1937. 

 Pythonella, Ray & Das-Gupta, 1937, p. 2. 



Oocyst develops sixteen sporocysts, each containing four 

 sporozoites. 



137, Pythonella bengalensis Ray & Das-Gupta. 



fPythonella bengalensis, Ray & Das-Gupta, 1937, p. 2, 



Oocysts spherical. Segmenting oocysts found in the 

 epitheHal cells of the intestine and in the fseces. Oocyst 

 develops eight primary sporoblasts, and after some time these 

 divide to form sixteen, and are converted into as many sporo- 

 cysts. Each sporocyst contains four sporozoites and a central 

 residuum . Male gametes are formed as in the family Eimeriidse . 

 Female gametes often seen lying in the submucosa. 



Dimensions. — Oocysts 25-30 fi in diameter ; sporocysts 8-10 /i 

 by 6-7^. 



Remarks. — Full description of this species has not yet been 

 pubhshed. Heccaidecasporocystid and tetrazoic condition 

 marks it out from all known Coccidia. Segmented or unseg- 

 mented oocysts were seen in the faecal matter and matured 

 within seven to ten days when kept in 1 per cent, chromic acid. 



Habitat. — Intestine of Python sp. : Bengal, Calcutta. 



Subfamily AGGREGATING Reichenow, 1929 

 (emend. Hoare, 1933). 



Schizogony in one type of host and sporogony in another. 

 Oocysts contain many sporocysts, each sporocyst giving 

 rise to from two to many sporozoites. 



Remarks. — Labbe (1899) founded the family Aggregatidse 

 to include the genus Aggregata. As originally defined by 

 Frenzel, Aggregata was a genus of Gregarines, characterized 

 by sporozoites being formed directly in the cyst round a number 

 of residual masses. The researches of Dobell (1914, 1925) 

 and Pixell-Goodrich (1924) showed that the Aggregatidse may 

 be safely regarded as Coccidia, which have their schizogony 

 in one host (usually a crab) and the sporogony in another 

 (usually a Cephalopod). It is now known that the bodies 

 produced in the cyst are merozoites, and not sporozoites 

 as was formerly supposed. 



