ON SOME OF THE FOSSIL TETTIGID^. 165 



treatises ; and also to those of Broclie, Hagen, Berendt, 

 and Goss, all of which are authoritative guides in this 

 department of biology. 



None but competent geologists can efficiently take 

 up the task of showing the sequence of any order of 

 life from its first appearance through its persistence to 

 present times ; and they, in their deductions therefrom, 

 will tread cautiously when so much must rest on 

 opinion. Still, as I have elsewhere attempted to 

 make such a sketch with reference to the closely- 

 allied family of Aphidinse ; whose appearance in the 

 world seems to have been synchronous with that of 

 Tettigidae, I offer here a few remarks ; with no special 

 claim to originality. Notwithstanding the assurance, 

 " Ne sutor ultra crepidam," this monograph may not 

 be injured by an attempt to put side by side notes of 

 some recent and fossil species. 



I commence, therefore, with notices of some of the 

 interesting examples of Homoptera, whose remains 

 have been discovered in the older sedimentary rocks 

 of Great Britain ; and then I proceed to describe a few 

 species of the chief genera marvellously preserved in 

 the fossil resin, known as amber. 



After a few remarks on the post-glacial age, I briefly 

 refer to the more recent deposits in resin-anime and 

 copal, which very well introduce us to the period when 

 modern species come into view, and we become 

 acquainted with living Cicadse. 



All rocks not igneous must be sedimentary, and have 

 an aqueous origin, either marine, fresh, or brackish. 

 The marine strata must largely predominate, inasmuch 

 as the sea has repeatedly covered all the land. Thus 

 as the lands now forming the continents at some time 

 must have been submerged, it is not difficult to see why 

 insects, the denizens of the land, have left fewer remains 

 in the rocks than have the numerous sea animals. This 

 paucity by no means proves that insects formerly did 

 not swarm over the tracts of dry ground from the 

 Devonian times upwards. It only shows that rocks of 



