FOSSIL CORIACEOUS AND MEMBRANOUS WINGS. 145 



beds at Erbignon in Switzerland, a fine cockroach, which 

 he considered to be one of the most ancient animals of 

 that country. He figures the wings, and names this 

 insect Blatta helvetica. It must have been quite two 

 inches long, excluding the antennae. Numerous Ter- 

 mites, and species belonging to the Orthoptera, were 

 also denizens of those coal forests and swamps.* 



The Hemiptera are nearly as ancient as the Coleo- 

 ptera, and apparently they take precedence of the Di- 

 ptera, Hymenoptera and Lepidoptera. 



The family types of insects are of vast antiquity, and, 

 what is not a little remarkable, all the remains of the 

 Arthropoda, hitherto discovered, have been referable to 

 existing orders. Yet, from Mr. Darwin we learn that 

 " from the continued tendency to divergence, the more 

 ancient a form is the more generally it differs from those 

 now living." This persistence of type in insects, it 

 must be admitted, does not furnish much direct evidence 

 in support of the theory of evolution of the higher 

 insects from lower forms. The oldest insects on record 

 were highly specialised, and in their organisation show 

 no inferiority to their modern representatives.! 



In a letter addressed to me, March, 1882, by Mr. S. 

 Scudder, he states that he " has now clear evidence of 

 the presence of the Heteropterous division of the 

 Hemiptera in America, in beds credited with being 

 Carboniferous. Certainly they are not younger than 

 the Permian period." 



It has been thought probable that the Homoptera, 

 which are less developed insects than the Heteroptera, 

 would have preceded the latter in time ; yet the occur- 

 rence of the latter at the earlier date as shown by 

 fossils would lead to the idea that the coriaceous wing 

 w r as an elaboration from the simpler membranous wing. 

 Although the oldest known Coleoptera and Dycteop- 

 tera possessed horny elytra, it cannot thus be proved 



* ' Die Urwelt der Scliweiz,' Prof. Oswald Heer, trans, by W. S 

 Dallas, 1876, vol. i, p. 20. 



f ' Geolog. Antiquity of Insects,' H. Goss, 1880, p. 4. 



VOL. IV. 10 



