550 GEOLOGICAL SURVEY OF THE TERRITORIES. 
EXPLANATION OF PLATE XVIII. 
Fic. 1. Apus equalis, 2, tenth foot. 
Fig. 2. Apus newberryi, 9, tenth foot, x, ‘subapical lobe.” 
Fiag.,3. Apus lucasanus, tenth foot, «, asin Fig. 2. 
Fic. 4. Apus longicaudatus, tenth foot. 
Fig. 5. Apus lucasanus, eleventh foot of the female, with the ovisac, containing a few 
eggs. 
Fia. 6. vy ae longicaudatus, eleventh foot of female. 
Fig. 7. Apus newberryi, eleventh foot of female. 
All the figures on this and Plates XIX-XXI much enlarged, and drawn by the author 
with the camera lucida. 
