INTRODUCTION. XXV 



with allied species belonging to other areas, but rather aimed at 

 differentiating the Ehynchota of British India alone. For this 

 purpose I have used colour differences wherever possible, so as to 

 facilitate identification by officers of the Government of India, 

 planters, travellers, and, in the strict sense, non-entomological 

 readers. AVith the same intention I have not attempted written 

 description of such details as the important but obscure odoriferous 

 apertures to be found on the metasternum. These by the aid of 

 joint effort with the artist have been so accurately portrayed, as 

 to prove that a good figure of a functional structure is far more 

 trustworthy than any diagnostic composition. 



The Rhtnchota, or Bugs (frequently styled Hemiptera), con- 

 stitute an extensive Oeder in the Class Insecta belonging to 

 the Phtlum ARTHROPODA, and are principally distinguished by 

 possessing a jointed suctorial I'ostrum — sometimes described as a 

 " proboscis or mobile beak " — formed from the labium, composed 

 of the mandibles and masilliB modified into a piercing-organ, and 

 usually concealed by being closely i-ecurved or bent back under 

 the head, sternum, or abdomen. The wings are almost constantly 

 four in number in the suborder Heteroptera (to which this volume 

 is restricted); the anterior wings are of a more or less coriaceous 

 texture, folded flat on the back, their apical areas being usually of 

 a membranous character. In the Homoptera, which will be sub- 

 sequently dealt with, the wings cover the abdomen in a roof-like 

 manner, and the anterior wings do not always exhibit a difference 

 in structure between the basal and apical portions *. 



The metamorphoses of the Ehynchota are somewhat varied, being 

 practically absent in the Heteroptera, in which the young in a 

 general or progressive manner resemble the adult ; in the Homo- 

 ptera the change may be very incomplete, as in the Cicadidse, or 

 almost complete, as among the male Scale-insects (Coccid®). As in 

 the order Obthoptera, the mouth does not change its structure 

 during the individual life, and Dr. Sharp on these grounds considers 

 the Orthoptera and Ehynchota as "the most different of all the 

 Orders," and the last as " the most isolated of all the orders of 

 Insects." Sharp places the Ehynchota after the Diptera and 

 Thysanoptera {Tlirips) at the end of the In::ecta ; Packard arranges 

 them between the Coleoptera and Orthoptera ; AVestwood between 

 the Lepidoptera and Aphauiptera and Diptera. If the views of 

 entomologists thus differ as to the position which the Ehynchota 

 should occupy in the classification of the Insecta, the most recent 

 writers on general zoology are also divided in opinion. Shipley 

 and MacBride place these insects between the Hymenoptera and 

 the Diptera ; Parker and Haswell dispose of them after the 

 Orthoptera and before the Diptera ; while Schmeil arranges them 



* Some writers include the Anoplura, or Lice, as a third suborder. 



