PLATE 8 



EXPLANATION OF FIGURES 



151 Blatta orientalis, showing different structures of mouth-parts. This 

 view is obtained by dissecting out the mouth-parts intact and arranging the 

 prepharynx so that the observer looks straight down into the mouth cavity. 

 In this way practically all the structures which belong to the mouth-parts can 

 be shown in one drawing. 



152 Blatta orientalis, ental aspect of the ventrocaudal part of hypopharynx 

 showing the c>uticular pouches, salivial bars and salivos. 



153 Blatta orientalis, lateral aspect of parapharynx. 



154 Blatta orientalis, sagittal section of head showing the lateral aspect of 

 prepharynx. 



155 Melanoplus differentialis, sagittal section of head showing the lateral 

 aspect of prepharynx. 



156 Melanoplus differentialis, lateral aspect of parapharynx. 



304 



