100 BRITISH CICADA. 



lately been published by Dr. David Sharp (Trans. Ent. 

 Soc. Lond., part iii. 1890). Numerous figures are 

 given ill my present Monograph, for exempUfymg 

 similar parts of the males in the Tettigidie, which are 

 members of the Homoptera. These parts, although 

 varying greatly in different species, may in a measure 

 be homologously collated, and shown to be related to 

 each other, species with species. It will be seen that 

 the suggestions Dr. Sharp puts forward, as to the 

 Heteroptera, in great measure apply to these groups of 

 the Homoptera. His observations really help us to 

 bring out of their apparent intricacies the complex 

 details of the pygofer so often alluded to in foregoing 

 pages, and to show us that they are not unique or 

 confined to the Heteroptera. 



Until, however, the corresponding parts of the 

 Typhlocybid^ have been figured, it will be premature 

 to discuss such a difficult subject as the signific?.uce 

 of the parts, or hazard anything as to the possible 

 function they may take in the economy of the insects. 



TYPHLOCYBIDiE.* 



This section of the Tettigidae is sharply separated 

 from the others by certain characters of the el}i,ra and 

 wings. The former organs are longer than the body, 

 and, with the exception of the genus Alehra, there is 

 no limbus or appendix to fold over the suture. These 

 elytra so cover the wings that they make the insect 

 appear cylindrical in form whilst seated at rest. The 

 ocelli are very rarely visible. The frons is long and 

 triangular. 



The species, as a rule, are small, but under the 

 microscope they are often elegantly and brightly 

 coloured. 



Some kinds are very abundant, and. through their 

 numbers in certain seasons, do some small injury to 



* The application of this term is not obvious ; but it may have 

 reference to the obscure cubical markings on the elytra of some species, 

 or else to the squarish form of the vertex. 



