Opalina. 315 
Attempts to infect two adult individuals of Zr2ton cristatus with 
cysts and adults of O. itestinalis failed, possibly because the newts 
did not swallow the Opalinae. The negative result cannot be trusted 
to show that such infection is difficult to secure. Contre & VaANrEy 
report Opalina intestinalis from Triton taeniatus. 
Opalina caudata gave exactly similar results with only the 
additional fact that adult Rana esculenta are abundantly infected 
from the cysts. Doubtless O. intestinalis cysts would infect adult 
Rana esculenta, but no such experiment was made. Opalina caudata 
has never been reported from Rana esculenta, nor from Rana tempo- 
raria, Bufo vulgaris, nor Hyla viridis. 
Opalina dimidiata cysts cause abundant infection of the tadpoles 
of Bufo vulgaris, Rana temporaria and Bombinator pachypus. Adult 
O. dimidiata cause abundant infection in tadpoles of the same species 
and in tadpoles of Rana esculenta. Rana esculenta is the usual host 
for O. dimidiata. Bufo vulgaris is also frequently infected with this 
species, but it has never been reported from Rana temporaria. 
Adult Opalina obtrigona cause abundant infection of tadpoles of 
Bufo vulgaris, Rana esculenta and Bombinator pachypus, though this 
parasite has never been reported from these species. 
Table showing results of infection experiments. 
| Asterisks indicate infections different from those known to occur 
in nature.| 
O. intestinalis cysts cause infection of Bombinator pachypus tadpoles. 
Bufo vulgaris tadpoles. * 
- = metamorphosing tadpoles. * 
Rana esculenta tadpoles. 
Rana temporaria tadpoles. * 
4 . adult.* 
Hyla viridis adult. * 
s: 2 adults* ,, : , the same tadpoles and adults. 
O. caudata cysts ~ - » Bombinator pachypus tadpoles. 
Bufo vulgaris tadpoles. * 
» e. metamorphosing tadpoles. * 
Rana esculenta tadpoles. * 
‘ 3 adult. * 
Rana temporaria tadpoles. * 
re . adult. * 
Hyla viridis adult. * 
4 »  adults* £ \ , the same tadpoles as the cysts. 
