INTRODUCTORY 



The present catalogue undertakes to give a complete enumeration 

 of all the described Hemiptera, to and including the Chermidae, 

 recorded from or known to occur in America north of the southern 

 boundary of the United States. The families Aphididae, Coccidae 

 and Aleurodidae have been omitted, largely because of the fact that 

 I have made no careful study of these groups and feel that others 

 are more competent to work out their synonymy. On account of 

 their different habits and the special methods required in observing, 

 collecting and preserving them, this omission is of little moment to 

 students of the higher families of the Hemiptera. 



The first draft of this catalogue was completed more than two 

 years ago and as there was then no prospect of its early publication, 

 a Check List giving the classification, synonymy and dates for all 

 the species was prepared and, through the kindness of Mr. Wm. T. 

 Davis of New York, was published lay the New York Entomological 

 Society. The introductory matter given below is largely a repetition 

 of that published in the Check List and the numbering of the species 

 in this catalogue has been made to correspond with that in the Check 

 List to facilitate ready reference from one to the other, the species 

 added since the publication of that list having been interpolated in 

 fractional form. A summary of the rules used by me in working 

 out the nomenclature of the catalogue was published in March, 1916, 

 in the Annals of the Entomological Society of America and need not 

 be repeated here. 



While perhaps less philosophical, it has seemed best to begin this 

 catalogue with the higher forms so as to bring it more into line with 

 such recent works as the Oshanin, Kirkaldy, and Lethierry and 

 Severin catalogues. For the Heteroptera the Reuter classification of 

 1912 has been followed very closely, but it has seemed desirable to 

 reduce a number of his families to subfamily rank. Unfortunately 

 the Homoptera have not been worked out with equal thoroughness, 

 but Hansen's studies seem to show conclusively that the Fulgoridae, 

 which I prefer for the present to retain as a single family, are the 

 highest and most specialized of the Homoptera. In this respect also 

 the Cicadidae appear to approach the Fulgoridae, but their develop- 



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