554 GEOLOGICAL SURVEY OF THE TERRITORIES. 



EXPLANATION OF PLATE XX. 



Fig. 1. Aptis newierryi, $ , first foot. 

 Fig. 2. Apus wqualis, $ , first foot. 

 Fig. 3. Apus longicaudatus, $ , first foot. 

 Fig. 4. Apus longicaudatus, ^, first foot. 



