HABITS AND STRUCTURE OF INSECTS. 



103 



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

 adjoining buildings blackened by the myriads 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 : 



Fig. 99.— Ga8-Po8t, with Ephemeea CLiNGraa to it. 



95. Another group of insects somewhat resembling the 

 Ephemera pass their larval state in the water. 



Some of their larvae are called caddis^orms, or case- 



