TEMPOEAEY PEEFACE. 



Some apology may be thought necessary for the 

 pubHcation of the present Monograph. It is not 

 supposed that it will lessen the value of existing 

 memoirs on this group of the Hemiptera-Homoptera, 

 such as those of Stal, Fieber, Sahlberg, and Edwards, 

 but rather that it will facilitate study of the group, 

 by enlarged portraitures of its species, and by a 

 selection of the more important results obtained by 

 authors of the last half century. 



In the interests of Science, all work is open to 

 criticism; but those who know the difficulties of 

 an intricate synonymy — involving in almost every 

 case patient comparisons, necessarily conducted under 

 the microscope — will not hastily condemn possible 

 errors in judgment in the identification of British 

 with foreign forms. 



To such a discriminating and not unkindly public, 

 the Author commends his endeavours. 



WEST, NEWMAN AND CO., PRINTERS, HATTON GARDEN, IiONDON, B.C. 



