>,1 



PREFACE TO PART I. 



This work has been prepared to meet the demand for a text- 

 book which shall enable students to acquire a thorough knowledge 

 of the elementary principles of Entomology, and to classify in- 

 sects by means of analytical keys similar to those used in Botany. 

 By means of the keys the student can readily determine to what 

 family any insect of which he has a specimen belongs. In many 

 cases tables of genera are also given ; and the more common or 

 conspicuous species in each family have been described. 



Although much pains has been taken to render easy the classifi- 

 cation of specimens, an effort has been made to give the mere deter- 

 mination of the names of insects a very subordinate place. The 

 groups of insects have been fully characterized, so that their relative 

 affinities may be learned ; and much space has been given to 

 accounts of the habits and transformations of the forms described. 

 As the needs of Agricultural students have been kept constantly 

 in view, those species that are of economic importance have been 

 described as fully as practicable, and particular attention has been 

 given to descriptions of the methods of destroying those that arc 

 noxious, or of preventing their ravages. 



The pronunciation of the technical terms has been indicated by 

 marking the accented vowel, and at the same time indicating its 

 length when the term is pronounced as an English word. 



All the illustrations not credited to other sources arc original, 

 and have been drawn and engraved by Mrs. Comstock. 



The specimens that have been studied in the preparation of this 

 work are nearly all in the collections of the Entomological Depart- 



