88 STKucTirr.E of adult insects. — the imago. 



a, clypeus ; 5, labrum ; c, mandibles ; d, maxillae ; «, labium ; 

 / labial palpi ; g, lingula of the labium. 



CHAPTER VI. 



the head. 



The Head is generally horny and round, and may be 

 studied as a whole in relation to its substa7ice,Jigure, com- 

 position^ articulation^ with the trunk motions, and espe- 

 cially as to its parts and appendages. 



We would consider the external anatomy of the head 

 under these three divisions, ^. e. : 



1. Os, or mouth. 



2. Facies, or tace — all the frontal and upper part of 

 the head ; and 



3. Sub-facies, including the under part of the head 

 and the neck. 



