THE OPALINID CILIATE INFUSORIANS. 



311 



America. (Fig. 239.) It is very probably present, though un- 

 reported, in southern and southeastern Asia, for it is in eastern Asia, 

 in the East Indies and in southern Africa. Its presence in eastern 

 and northern North America is improbable, for a rather broadly 



representative group of Anura from these localities have been ex- 

 amined. The reason for its absence from this area is not under- 

 stood. Cepedea also is apparently absent from this region. The 

 wide distribution of Protoopalina indicates that it is an old genus, 



