742 MUIllEL ROBERTSON. 



an account of some of the processes which take place in the 

 intermediate host, the leech Ozobranchus shipleyi. 



I. Occurrence of the Parasite. 



Nicoria trijuga occurs in very large numbers all over 

 Ceylon. It generally frequents ponds, lakes, and rivers, but 

 specimens are sometimes found living a semi-terrestrial exist- 

 ence in places removed from water. The tortoises which 

 have adopted the drier habitat occasionally show ticks, but I 

 have never found them infected with the haemogregarine. I 

 did not, however, examine a sufficiently large number of 

 individuals to be able to draw the conclusion that the dry- 

 dwelling tortoises are never infected. 



The Nicorias from the usual aquatic habitat are very often 

 infected with the liasmogregarine. It does not seem to 

 produce any pathogenic effects even when pi-esent in large 

 numbers. No other blood-parasites were ever observed in 

 association with the htemogregarine. The intestinal parasites 

 were not investigated, but it may be noted in passing that a 

 Bodo-like flagellate was found on two occasions in the gall- 

 bladder. 



The only ectopai*asites present were ticks on dry-land 

 tortoises and leeches on the water-dwelling tortoises. The 

 leeches belonged to a species of Ozobranchus; only once 

 was an isolated Glossiphonia found upon a Nicoria. I 

 found that tortoises from all parts of Ceylon sliowed the 

 liEemogregarine. I never, however, investigated individuals 

 from more than an elevation of 1500 feet. Generally speak- 

 ing I found the up-country reptiles were free from blood- 

 parasites. 



II. Brief Summary of the Life-history. 



For the sake of clearness it is, I think, advisable to give a 

 brief account of the life-history of the form under discussion, 

 in so far as it has been made out, before treating the various 

 points in detail. 



