546 GEOLOGICAL SURVEY OF THE TERRITORIES. 
EXPLANATION OF PLATE XVI. 
Fig. 1. Lepidurus glacialis, enlarged nearly 3 times. la, upper, 1b, under side of the 
telson enlarged. 
Fic. 2. Apus lucasanus Packard, nat, size. 2a, upper; 2b, under side of telson, en- 
larged. 
Fig. 3. Apus newberryi Packard, nat. size. 3a, upper; 3b (on right-hand.side), under 
side of telson, enlarged. 
Fic. 4. dpus longicaudatus Le Conte, upper, 4a, under side of telson. 
Fic. 5. Apus himalayanus Packard, telson. 5a, under side of telson, enlarged. 
Drawn by J. H. Emerton. 
