TEMPORARY POND COMMUNITIES 175 
SEMI-TEMPORARY POND OR MARSH AND INHABITANTS 
General view of Pond 93, which is occupied by Sagittaria and grass- 
BiG. 123. 
like plants. 
Fic. 124.—Side view of a red-winged blackbird’s nest. Photo by T. C. Stephens. 
Fic. 124a.—The same from above. 
Fic. 125.—A temporary pond form of the snail (Lymnaea reflexa); natural size. 
