OBSERVATIONS ON HM@MATOZOA IN CEYLON. 389 
named Hemocystidium metschnikovi (Simond) re- 
sembles the parasite of the gecko in general features but 
differs markedly from it in point of size, rarely exceeding the 
half of the corpuscle in diameter, in the smaller number of 
pigment granules, and in the fact that it does not cause a 
displacement of the nucleus of the corpuscle, according to 
Dr. Simond’s figures. Double or even treble infections of a 
corpuscle by H. metschnikovi do not affect the outline of 
the latter. It is, therefore, clearly a smaller species than 
H. simondi. 
The natures of the hosts are also widely different, the one 
an aquatic chelonian, the other a terrestrial gecko living in 
the driest province of Ceylon. 
The same species of gecko whose blood is infected with 
Hemocystidium simondi harbours a nematode parasite 
in its intestine, which has been described by Dr. von Linstow 
as a new species of Oxyuris, O. megaloon.! 
II]. HamMoGREGARINE OF NICORIA TRIJUGA. 
The hemogregarines as a whole appear to favour foul- 
feeding animals, and there are few fouler feeders than 
Nicoria trijuga, a tortoise with amphibious habits com- 
monly met with in the ditches and marshy lands round 
Colombo and in the Colombo Lake. 
The larger specimens of this tortoise are generally found 
to be infected with a hemogregarine which does not show any 
particularly striking properties distinguishing it from other 
similar species. It is, however, important to establish the 
fact of its almost constant occurrence in a host which derives 
its nourishment largely from offal. 
The tortoise also harbours Nematode parasites in its intes- 
tine which have been kindly named and described by Dr. von 
Linstow as a new species of Oxysoma, O. falcatum.’ 
1 The description of this species will shortly appear in ‘ Spolia Zeylanica.’ 
2 For early publication in ‘ Spolia Zeylanica.’ 
