THE GENUS DENDROCTONUS. 



65 



Epistoma^ 

 Clypeus 

 Labrum-t- 



Head 



FIG. 43.Dendroctonv3 valens: Digestive organs of larva. 

 A , Fore intestine; , mid intestine; C, hind intestine; 

 a, mouth ; 6, anterior section of mid intestine; c, median 

 section; d, posterior section; e, small intestine;/, ccecal 

 glands; g, anus; 9th, ninth segment; 10th, tenth segment; 

 ft, base of the 2 malpighian tubules; i, base of the 4 

 malpighian tubules. (Original.) 



