78 ILLINOIS BIOLOGICAL MONOGRAPHS [358 



Parampliistomidae 



Paramphistominae 



Paramphistomum 



Cotylophoron 

 Cladorchinae 



Claclorcliis 



Taxorchis 



Chiorchis 



Microrchis 



Pseudocladorehis 



Pseudodiscus 



Balanorchis 



Watsonius 



Pfenderius 

 Diplodiscinae 



Diplodiscus 



Catadiscus 



Opisthodiscus 

 Stephanopharynginae 



Stephanopharynx 



As a result of my studies on this family, certain data have been 

 added and some doubtful points cleared up. The discovery of the two 

 species of the new genus Alassostoma and the demonstration of their po- 

 sition as members of a new genus in the subfamily Schizamphistominae 

 Looss establishes that group. The description of the new genus and 

 species Zygocotyle ceratosa throws considerable light on the previously 

 isolated and obscure species A. lunatum Dies. In conclusion I present 

 a tentative revision of the paramphistomes. In the main it is my inter- 

 pretation of the status of the group and its subdivisions. The new genera 

 of Stiles and Goldberger are included without comment altho certain au- 

 thors do not recognize their validity. I have had no opportunity to work 

 on this material and consequently any judgment on my part must appear 

 unwarranted. Because of the scarcity of known forms and the incom- 

 pleteness of most of the descriptions it is impossible to present a final 

 classification. The following arrangement is provisional and likely to 

 be replaced whenever a natural system can be formulated for the family. 



Paramphistomidae Fischoeder 1901 

 Gastrodiscinae Monticelli 1892 

 Gastrodiscus 

 Homalogaster 

 Paramphistominae Fischoeder 1901 



