348 NATURAL HISTORY OF AQUATIC INSECTS CH. 



Fig 103. — I, Gerris thoracica (the centre of the thorax should be paler); 2, wing- 

 less imago of Gerris najas?; 3, hind wing of G. thoracica; 4, rostrum of 

 do. ; 5, transverse section of abdomen of G. najas. 



