INTRODUCTION V 



Primary homonyms of species have been replaced by nomina nova; 

 secondary homonyms have been restored to their original names if the 

 homonymy has been relieved by moving one or the other, or both 

 species, to other genera. 



All specitic endings have been modified to agree with the suggestions 

 made by Blackwelder 1940, Journal of the Washington Academy of 

 Sciences 31; 135-140. There are certain disadvantages inherent in 

 this method, but it seems to the writer that these limitations are out- 

 weighed by the advantages. We are confronted by so many coined 

 words that can have no gender it seems better to use this system and 

 disregard apparent violations of Latin and Greek grammar. Where 

 the gender of generic names can be determined, the appropriate ad- 

 justments are made in the specific names. 



In a detailed catalogue such as this it is practically impossible to 

 eliminate all errors. We will appreciate it very much if our attention 

 is directed to all such mistakes. It is especially easy to overlook lists 

 published in the proceedings of local natm^al history societies, refer- 

 ences to species of economic importance published in scientific agri- 

 cultural journals, references to vectors of plant diseases published in 

 phytopathological journals, and references of a similar nature. It 

 will be very much appreciated if authors will send us reprints of all 

 articles dealing with the Homoptera. Also, it would seem that no 

 changes in the nomenclatm'e adopted in this catalogue should be made 

 in the future without a full explanation. 



All literature available to the writer before December 31, 1955, has 

 been included in this catalogue. 



The present catalogue of the Family Nirvanidae is the seventh part 

 of the Cicadelloidea. This was virtually complete at the time of the 

 death of Dr. Z. P. Metcalf on January 5, 1956. It was completed 

 with the aid of Miss Virginia Wade, research analyst. North Carolina 

 State College, who worked with Dr. Metcalf for 7 years, and the 

 technical advice of Dr. David A. Young, North Carolina State 

 College, and Dr. P. W. Oman, formerly in charge of the Insect Identi- 

 fication and Parasite Introduction Research Branch, Entomology 

 Research Division, AgTicultural Research Service, U.S. Department 

 of Agriculture, Beltsville, Md. The higher categories utilized in this 

 classification are those decided upon by Dr. Metcalf during his work 

 on the catalogue. 



In this part of the catalogue a method of literature citation has been 

 adopted which differs from that used in the catalogues of the fulgoroid 

 families. References are cited by author, year, and key letter, e.g., 

 Fabricius 1802a. The full reference can be obtained by consulting the 

 Bibliography of the Cicadelloidea, in which authors are arranged 

 alphabetically, and their works chronologically under the author's 



