Ixxviii INTRODUCTION. 



Miscellaneous Notes. 



A few remarks may be here added as to the aspect 

 under which the Insects have been drawn in the plates 

 of this Monograph. 



It will be readily understood that the relative parts 

 of objects, viewed under the camera lucida, must 

 vary with their perspective positions. It may be 

 well, therefore, here to state that the dorsal aspect, 

 when mentioned, relates to the view from above, the 

 Cauda being turned towards the observer. The ventral 

 aspect is similar in position, but viewed from below. 

 The facial aspect represents the Insect with its frons or 

 face turned to the observer in such a manner, that the 

 frons, clypeus, and rostrum can be seen all, or nearly 

 all, in the same plane" and focus. It thus will appear 

 that parts like the genitalia may change their apparent 

 form under different aspects. 



The length of the head means the distance between 

 the vertex and the neck, even though this space may 

 be shorter than that between the eyes. The breadth 

 of the head consequently means the space from right 

 to left. Thus in Idioccrus the head is much broader 

 than it is long. 



Dismemberment of the smaller Tettigidae is often 

 necessary to prepare the details of parts for microscopic 

 examination. These disjointed parts need not be lost. 

 They almost always may be preserved on glass slips, 

 and covered with Canada balsam. 



