Introductory 



name, Mononyehidae, which would have changed the type of the 

 family to Mononyx. Logically, we have no more right to change the 

 type of a family than of a genus or a species. 



Every one who has given the matter any study will agree that 

 most changes in generic names come from one of two causes ; changes 

 in the accepted dates of the books in which they were published and 

 diversity of method in the selection of geno-types. In the matter 

 of dates I have accepted no changes unless I could feel satisfied that 

 they were justified. There will be no uniformity in this matter until 

 there is an official bibliography with all dates validated by an inter- 

 national committee, a consummation that I fear is still far in the 

 future. Regarding geno-types I have followed the International 

 Rules as closely as I could interpret them. As a basis I have accepted 

 the type fixations in five of the earlier works in all cases where but 

 one type was named. Where two or more were named I have rejected 

 them all and accepted the next valid single fixation. The five works 

 referred to are: Lamarck, Systeme des animaux sans vertebres, 1801; 

 Fabricius, Systema Rhyngotorum, 1803 ; Latreille, Considerations 

 generales sur Tordre naturel des animaux, 1810; Laporte, Essai d'une 

 classification systematique de Tordre des Hemipteres, 1832; and West- 

 wood, Introduction to tlie modern classification of insects : Synopsis, 

 at end of vol. 2, 1840. These type-fixations have, I think, been 

 accepted by Dr. Renter and other European Hemipterists and prob- 

 ably are open to as few objections as any cases where the type species 

 is not named in so many words in connection with each individual 

 genus. All these writers, with tlie possible exception of Fabricius, 

 stated that they were naming types for the genera and we have 

 Fallen for authority that he was doing so. Kirkaldy claims that 

 Fabricius indicated types for his genera in the Entomologica Sys- 

 tematica in the same way that he did in his Systema Rhyngotorum. 

 but he really made such a designation by repeating generic characters 

 in his specific descriptions in the case of but very few hemipterous 

 genera, and then without italics, and in his later work he omitted some 

 of these and changed others; hence there seems to be no valid reason 

 why we should accept these earlier ones as tyi)e-fixations. 



I have here accepted the classification of geno-types devised by 

 Mr. 0. F. Cook and published in May, 1914. in the American Natur- 

 alist. These terms are : 



Orthotype, a type l)y original designation. 



Haplotype, a type by single reference (only species). 



