PARASITIC PROTOZOA FROM CEYLON. 67 
Castellani and Willey also failed to find trypanosomes in the 
blood of Ophiocephalus striatus, though they note that Lingard 
found trypanosomes in this species in India. 
The same observers also record a trypanosome as occurring in 
the blood of Gobius giuris, although—as recorded above—the four 
individuals of this species which I examined proved negative. 
Castellani and Willey also record a trypanosome from Macrones 
cavasius, a Silurid. 
AMPHIBIANS. 
The common frog, Rana tigrina, is the only amphibian in which 
I have found blood parasites. 
A.—I nfected. 
1. Rana tugrina.—My records are as follows :—Two individuals 
(Colombo, July), both infected with trypanosomes and hemo- 
gregarines. One individual (Colombo, July) infected with hemo- 
gregarines only.. ‘Two individuals (Colombo, Aug.), blood negative. 
One very young specimen (Peradeniya, Aug.), blood negative. 
Two individuals (Colombo, Sept.), blood of both negative. 
B.—Not infected. 
2. Bufo melanostictus. — Three individuals (Colombo, .July). 
One young individual (Peradeniya, Aug.). 
3. Izalus leucorrhinus—A single specimen from Peradeniya 
(Aug.). 
4. Rhacophorus maculatus—One individual from Peradeniya 
(Aug.) and one from Trincomalee (Sept.). 
Comments —Castellani and Willey examined R. tigrina, with 
negative results. The parasites which I encountered are therefore 
recorded for the first time from Ceylon frogs. I have little doubt 
that the hamogregarine which I found in R. tigrina is the same as 
that described from this species in Bombay by Berestneff (1903), 
and named Hemogregarina berestneffi by Castellani and Willey 
(1905).* I encountered intracorpuscular individuals of various 
forms and sizes, many of them showing the characteristic pink- 
staining sheath described by Berestneff. In addition to these forms, 
there were also many free gregariniform individuals in the blood 
‘plasma. These were actively motile. I several times observed 
small forms enter red blood corpuscles. They did this by boring 
directly into the corpuscle, very much in the way described by 
Schaudinn (1903) in the case of the sporozoites of Plasmodium 
vivax, but the time taken was very different, as entry was effected 
in a few minutes. Occasionally, the animal, after reaching the 
inside of the corpuscle, rested for a few minutes and then wriggled 

* Patton (1908) states that he has ‘‘ had the opportunity of studying no 
less than five hemogregarines in Rana tigrina and Rana hexadactyla, not only 
in the frogs, but in the leech which transmits them.” 
