20 INTRODUCTION, 



closely to the Orthoptera, with which they agree in their 

 partial transformations, and active pupae. They form the 

 little order DERM AFTER A of Leach, or EUPLEXOPTERA of 

 Westwood. 



The spider-flies, bird-flies, sheep-tick, &c. (Hippoboscadce*), 

 which, with Latreille and others, I have retained among the 

 Diptera, form the order HOMALOPTERA of Leach, and the 

 English entomologists. 



The May-flies, or case-flies (Phryganeadce), have been 

 separated from the Neuroptera ; and constitute the order 

 TRICHOPTERA of Kirby. Latreille and most of the natu- 

 ralists of the continent of Europe still retain them in 

 Neuroptera, to which they seem properly to belong. 



The Thrips tribe consists of minute insects more closely 

 allied to Hemiptera than to any other order, but resembling 

 in some respects the Orthoptera also. It forms the little 

 order THYSANOPTERA of Haliday ; but I propose to leave it, 

 as Latreille has done, among the Hemiptera. 



The English entomologists separate from Hemiptera the 

 cicadas or harvest-flies, lantern-flies, frog-hoppers, plant-lice, 

 bark-lice, &c., under the name of HOMOPTERA ; but these 

 insects seem too nearly to resemble the true Hemiptera to 

 warrant the separation. 



Burmeister, a Prussian naturalist, has subdivided the Neu- 

 roptera into the orders NEUROPTERA and DICTYOTOPTERA, 

 the latter to include the species which undergo only a partial 

 transformation. If Hemiptera is to be subdivided, as above 

 mentioned, then this division of Neuroptera will be justifiable 

 also. 



Objections have often been raised against the study of 

 natural history, and many persons have been discouraged 

 from attempting it, on account of the formidable array of 

 scientific names and terms which it presents to the beginner ; 

 and some men of mean and contracted minds have made 

 themselves merry at the expense of naturalists, and have 

 sought to bring the writings of the latter into contempt, be- 



