Preface. vii 



form. His method would have thrown out a large number of groups 

 founded by Amyot and Servillc in their great work which is really 

 the foundation of all our modern classification of the Hemiptera. In 

 brief Dr. Horvath's scheme as worked out in this List is this: All 

 groups higher than genera up to and including superfamilies are 

 named from some genus which genus becomes the type of such group, 

 and the group name must follow that of the type genus through all its 

 subsequent mutations. Thus the family Galgulidrc was founded in 

 1820 on genus Galgulus which later became Gelastocoris, thus chang- 

 ing the name of the family to Gelastocoridse. We cannot shift ovei 

 to Mononychidae, the next oldest name, as was suggested by Dr. 

 Horvath, as that would change the type genus and really the whole 

 character of the family. 



For these higher groups I have adopted the terminations suggested 

 by the International Committee: idcr for families; iiiar for subfamilies, 

 ini for tribes and aria for divisions. For superfamilies the termina- 

 tion idea has been employed. It should be noted here that the divi- 

 sions of Stal, Renter and Distant become tribes by this arrangement. 



In the nomenclature of the genera a few questions arose for which 

 I could find no answer among the decisions of the International Com- 

 mittee and in such cases I was obliged to use my best judgment. Foi 

 one thing I have refused absolutely to accept as valid any genus for 

 which no type species can be fixed under the International Rules. 

 A genus founded, even if described, without the mention of an in- 

 cluded valid species is a nomen nudum until a species has been as- 

 signed to it and then the genus dates from the inclusion of such 

 species. If we were to accept as valid a genus without a type we 

 j)ractically iirralidatc our entire jdan of genotypes and foimd our sys- 

 tem on usage instead; a rule which certainly would prove far more 

 difficult in its application, even if stability by this plan were possible, 

 which is questionable. 



It has not always been found easy to determine just what consti- 

 tutes the naming of a genotype. Of the earlier works I have accepted 

 the following five as naming genotypes, as they are systematic works 

 and their authors distinctly state that they are indicating the type or 

 typical species. These works are : Lamarck, Systeme des Animaux 

 sans Vertebres, 1801 ; Fabricius, Systema Rhyngotorum, 1803; 



