﻿HABITS AND STRUCTURE OF INSECTS. 



103 



great lakes it is a common sight to see the gas-posts and 

 adjoining buildings blackened by the myi'iads of Ephemera 

 which have been blown in from the lakes and have been at- 

 tracted by the lights. The following figure represents a 

 gas-post, in Cleveland, Ohio, as it appeared with Ephemera 

 clinging to it : 



Ftg. 99.— Gas-Post, with Ephemeba clingikg to rr. 



95. Another group of insects somewhat resembling the 

 Ephemera pass their larval state in the water. 



Some of their larvse are called caddis-worms^ or case- 



