232 



Arthropoda. 



lip and tliree pairs of jaws occur. The upper lip (lab rum) 

 is a broadj movable unpaired plate, situated in front of the 

 mouth. Behind the labrum are the mandibles, which are Tery 



o 



t^ C^v^ 



Fig. 195. Diagrams of the month parts of various Insects. A An Insect with h i t i n g 

 mouth-parts, B a Butterfly, Oa Fly. 1 labrum, 2 mandible, 3 first maxilla, 

 c cardo, s stipes, /' galea, /" lacinia, p^ palp. 4 Second maxilla = labium, c submentum, 

 s mentum, /'glossa, /" paraglossa of Ugula, p palp, / proboscis of B and 0. — Orig. 



much like those of the Crustacea in general structure, though as 

 the palp is always wanting, each consists of a single, unsegniented_ 

 piece, which can be moved inwards (towards the middle line) or 

 outwards J its inner surface forms a cutting edge, and at its base 



