After becoming briefly acquainted with the nature of 



occurrence of monogenetic trematodes on amphibians and reptiles we can 

 note that here also are observed the same normalities (regularities, nobis) 

 as those which were established by us for the occurrence of Mono- 

 genoidea among fishes. This pertains to the occurrence of the species 

 just as the genera of both families. Oculotrema hippopotami (Stunkard) about 

 which we have already spoken (see page 21';) may be an exception for Polystomatidae. 



S24 



