PLATE 9 



EXPLANATION OF FIGURES 



157 to 163 Mouth-parts, arranged in the same way as in figure 151. 



157 Gryllus pennsylvanicus. 



158 Orchelimum vulgare. 



159 Stenopehnatus sp. 



160 Tettix arenosus. 



161 Mantis religiosa. 



162 Melanoplus differentialis. 



163 Diapheromera femorata. 



306 



