550 GEOLOGICAL SURVEY OF THE TERRITORIES. 



EXPLANATION OF PLATE XVIII. 



Fig. 1. Apus cequalis, 9 , tenth foot. 



Fig. 2. Apus nmvlerryi, 9 , tenth foot, x, "subapical lobe." 



Fig. 3. Apus lucasanus, tenth foot, x, as in Fig. 2. 



Fig. 4. Apu^ longicaudatus, tenth foot. 



Fig. 5. Apus lucasanus, eleventh foot of the female, with the ovisac, containing a few 



eggs. 

 Fig. 6. Apus longicaudatus, eleventh foot of female. 

 Fig. 7. Apus netvherryi, eleventh foot of female. 

 All the figures on this and Plates XIX-XXI much enlarged, and drawn by the author 



with the camera lucida. 



