INTRODUCTION. O 



or rounded, and its breadth may be relatively great or the 

 contrary ; the amount of the extension beyond the coxae varies in 

 different genera. 



The elytra are totally absent in Anisolabis, the Brachylabime, 

 and certain other genera not occurring in India. In the normal 

 development they are more or less rectangular, veinless, chitinous 

 flaps. They are attached to the mesonotum, and in repose lie in 

 a horizontal position over the dorsal surface of the insect, the 

 sutural margins of the two elytra being contiguous and conse- 

 quently forming a median suture. They are divided into a broad 



sternal plates. 



. Penultimate ventral 

 segment. 



Pygidium. 



Fig. 1 a. — Diagram of ventral aspect of au Earwig. 



dorsal area or disc, and a narrow costal portion, which, in repose, 

 assumes a vertical position along the Hanks of the thorax. These 

 two portions are sharply separated from each other by a distinct 

 keel in Lahidura, Forcijnda, AUodahlia and some other genera ; 

 but as a rule there is no sharp line of demarcation, the areas 

 passing gradually into each other. In a good many genera the 

 shoulders of the elytra are rather prominent, rounded and pro- 

 jecting beyond the sides of the pronotum, but when the wings are 



