INSECTS. 



119 



Similar cases encrusted with carbonate oflinie are found in 

 Auvergne, in France, forming strata six feet ill thickness, and 

 extending over a considerable area.* 



r \ 



Fig. 103. EPHEMERA. 



The Ephemera (Fig. 103), whose brief period of existence 

 in its perfect state has become proverbial, belongs also to this 

 division. He who reads Dr. Franklin's charming paper f con- 

 taining the soliloquy of an aged Ephemera, who had lived 

 " no less than four hundred and twenty minutes," will ever 

 afterwards look with interest upon the insect which has been 

 made the means of conveying a lesson so true and so com- 

 prehensive. 



TIYMENOPTERA4 



Fig. 104. TKNTIZKEDO. 



Fig. 105. lO 



The insects of this order have four veined membranous 

 wings, but they are not equal in size, nor are they reticulated, 



* Lyell. Principles of Geology, vol. iv. page 105. 

 f The Ephemera, an Emblem of Human Life. 



From two Greek words; one signifying a membrane, the other a 

 wing, all the four wings being membranous. About 1100 Irish species. 



