24 e 



Canadian Arctic Expedition, 1913-18 



EXPLANATION OF PLATE II. 



Plate 1. Bark-bBetles. 



Fig 

 Fig 

 Fig 

 Fig 

 Fig 

 Fig 



1. Carphoborus aridersoni Sw. 



2. Polygraphus rufipennis Ivy. 



3. Pityophthorus nitidus Sw. 



4. Pityophthorus nitidus Sw., declivity of elytra. 



5. Pityophthorus nitidus Sw. 



6. Dmdroctonus johanseni Sw. 



The drawings are by Mr. A. E. Kellett, Artist Assistant. Entomological Branch, Department 

 of Agriculture, < )ttawa. 



